andersen/cis-benchmarks
1
0 Fork 0
mirror of https://git.valherun.com/valherun/cis-benchmarks.git synced 2026-10-15 19:42:03 -04:00
Code Issues Packages Projects Releases Wiki Activity
Files
bc5f96dd2d28207ee7ce8bb0146282e736bb2d62
cis-benchmarks/text/CIS_Docker_Benchmark_v1.8.0.txt
T

10671 lines
542 KiB
Plaintext
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
CIS Docker Benchmark
v1.8.0 - 07-24-2025
Internal Only - General
Terms of Use
Please see the below link for our current terms of use:
https://www.cisecurity.org/cis-securesuite/cis-securesuite-membership-terms-of-use/
For information on referencing and/or citing CIS Benchmarks in 3rd party documentation
(including using portions of Benchmark Recommendations) please contact CIS Legal
([email protected]) and request guidance on copyright usage.
NOTE: It is NEVER acceptable to host a CIS Benchmark in ANY format (PDF, etc.)
on a 3rd party (non-CIS owned) site.
Page 1
Internal Only - General
Table of Contents
Terms of Use .................................................................................................................. 1
Table of Contents........................................................................................................... 2
Overview ......................................................................................................................... 7
Important Usage Information .................................................................................................. 7
Key Stakeholders .................................................................................................................................. 7
Apply the Correct Version of a Benchmark ........................................................................................ 8
Exceptions ............................................................................................................................................. 8
Remediation ........................................................................................................................................... 9
Summary ................................................................................................................................................ 9
Target Technology Details..................................................................................................... 10
Intended Audience ................................................................................................................. 10
Consensus Guidance ............................................................................................................. 11
Typographical Conventions .................................................................................................. 12
Recommendation Definitions ..................................................................................... 13
Title .......................................................................................................................................... 13
Assessment Status ................................................................................................................ 13
Automated............................................................................................................................................ 13
Manual .................................................................................................................................................. 13
Profile ...................................................................................................................................... 13
Description .............................................................................................................................. 13
Rationale Statement ............................................................................................................... 13
Impact Statement.................................................................................................................... 14
Audit Procedure...................................................................................................................... 14
Remediation Procedure ......................................................................................................... 14
Default Value ........................................................................................................................... 14
References .............................................................................................................................. 14
CIS Critical Security Controls® (CIS Controls®) ................................................................... 14
Additional Information ........................................................................................................... 14
Profile Definitions ................................................................................................................... 15
Acknowledgements ................................................................................................................ 16
Recommendations ....................................................................................................... 17
1 Host Configuration .............................................................................................................. 17
1.1 Linux Hosts Specific Configuration ............................................................................................ 18
1.1.1 Ensure a separate partition for containers has been created (Manual) .......................... 19
1.1.2 Ensure only trusted users are allowed to control Docker daemon (Manual) ................... 21
1.1.3 Ensure auditing is configured for the Docker daemon (Automated)................................ 23
Page 2
Internal Only - General
1.1.4 Ensure auditing is configured for Docker files and directories - /run/containerd (Manual)
................................................................................................................................................. 25
1.1.5 Ensure auditing is configured for Docker files and directories - /var/lib/docker (Manual) 27
1.1.6 Ensure auditing is configured for Docker files and directories - /etc/docker (Automated)
................................................................................................................................................. 29
1.1.7 Ensure auditing is configured for Docker files and directories - docker.service
(Automated) .............................................................................................................................. 31
1.1.8 Ensure auditing is configured for Docker files and directories - containerd.sock
(Automated) .............................................................................................................................. 33
1.1.9 Ensure auditing is configured for Docker files and directories - docker.sock (Automated)
................................................................................................................................................. 35
1.1.10 Ensure auditing is configured for Docker files and directories - /etc/default/docker
(Automated) .............................................................................................................................. 37
1.1.11 Ensure auditing is configured for Docker files and directories - /etc/docker/daemon.json
(Automated) .............................................................................................................................. 39
1.1.12 Ensure auditing is configured for Docker files and directories -
/etc/containerd/config.toml (Automated) ................................................................................... 41
1.1.13 Ensure auditing is configured for Docker files and directories - /etc/sysconfig/docker
(Automated) .............................................................................................................................. 43
1.1.14 Ensure auditing is configured for Docker files and directories - /usr/bin/containerd
(Automated) .............................................................................................................................. 45
1.1.15 Ensure auditing is configured for Docker files and directories - /usr/bin/containerd-shim
(Automated) .............................................................................................................................. 47
1.1.16 Ensure auditing is configured for Docker files and directories - /usr/bin/containerd-shim-
runc-v1 (Manual) ...................................................................................................................... 49
1.1.17 Ensure auditing is configured for Docker files and directories - /usr/bin/containerd-shim-
runc-v2 (Automated) ................................................................................................................. 51
1.1.18 Ensure auditing is configured for Docker files and directories - /usr/bin/runc
(Automated) .............................................................................................................................. 53
1.2 General Configuration .................................................................................................................. 55
1.2.1 Ensure the container host has been Hardened (Manual)................................................ 56
1.2.2 Ensure that the version of Docker is up to date (Manual) ............................................... 58
2 Docker daemon configuration............................................................................................ 60
2.1 Run the Docker daemon as a non-root user, if possible (Manual) ..................................... 61
2.2 Ensure network traffic is restricted between containers on the default bridge (Manual) .... 63
2.3 Ensure the logging level is set to 'info' (Manual) ................................................................ 65
2.4 Ensure Docker is allowed to make changes to iptables (Manual) ...................................... 67
2.5 Ensure insecure registries are not used (Manual).............................................................. 69
2.6 Ensure aufs storage driver is not used (Manual)................................................................ 71
2.7 Ensure devicemapper storage driver is not used (Manual) ................................................ 73
2.8 Ensure TLS authentication for Docker daemon is configured (Manual) ............................. 75
2.9 Ensure the default ulimit is configured appropriately (Manual) .......................................... 77
2.10 Enable user namespace support (Manual) ...................................................................... 79
2.11 Ensure the default cgroup usage has been confirmed (Manual)...................................... 81
2.12 Ensure base device size is not changed until needed (Manual) ...................................... 83
2.13 Ensure that authorization for Docker client commands is enabled (Manual) ................... 85
2.14 Ensure centralized and remote logging is configured (Manual) ....................................... 87
2.15 Ensure containers are restricted from acquiring new privileges (Manual)........................ 89
2.16 Ensure live restore is enabled (Manual) ........................................................................... 91
2.17 Ensure Userland Proxy is Disabled (Manual) ................................................................... 93
2.18 Ensure that a daemon-wide custom seccomp profile is applied if appropriate (Manual) . 95
2.19 Ensure that experimental features are not implemented in production (Manual) ............. 97
3 Docker daemon configuration files ................................................................................... 99
3.1 Ensure that the docker.service file ownership is set to root:root (Automated) ................. 100
3.2 Ensure that docker.service file permissions are appropriately set (Automated) .............. 102
Page 3
Internal Only - General
3.3 Ensure that docker.socket file ownership is set to root:root (Automated) ........................ 104
3.4 Ensure that docker.socket file permissions are set to 644 or more restrictive (Automated)
............................................................................................................................................... 106
3.5 Ensure that the /etc/docker directory ownership is set to root:root (Automated).............. 108
3.6 Ensure that /etc/docker directory permissions are set to 755 or more restrictively
(Automated) ............................................................................................................................ 110
3.7 Ensure that registry certificate file ownership is set to root:root (Manual) ........................ 112
3.8 Ensure that registry certificate file permissions are set to 444 or more restrictively (Manual)
............................................................................................................................................... 114
3.9 Ensure that TLS CA certificate file ownership is set to root:root (Manual) ....................... 116
3.10 Ensure that TLS CA certificate file permissions are set to 444 or more restrictively
(Manual) ................................................................................................................................. 118
3.11 Ensure that Docker server certificate file ownership is set to root:root (Manual) ........... 120
3.12 Ensure that the Docker server certificate file permissions are set to 444 or more
restrictively (Manual) .............................................................................................................. 122
3.13 Ensure that the Docker server certificate key file ownership is set to root:root (Manual)
............................................................................................................................................... 124
3.14 Ensure that the Docker server certificate key file permissions are set to 400 (Manual). 126
3.15 Ensure that the Docker socket file ownership is set to root:docker (Automated) ........... 128
3.16 Ensure that the Docker socket file permissions are set to 660 or more restrictively
(Automated) ............................................................................................................................ 130
3.17 Ensure that the daemon.json file ownership is set to root:root (Manual) ....................... 132
3.18 Ensure that daemon.json file permissions are set to 644 or more restrictive (Manual).. 134
3.19 Ensure that the /etc/default/docker file ownership is set to root:root (Manual)............... 136
3.20 Ensure that the /etc/default/docker file permissions are set to 644 or more restrictively
(Manual) ................................................................................................................................. 138
3.21 Ensure that the /etc/sysconfig/docker file permissions are set to 644 or more restrictively
(Manual) ................................................................................................................................. 140
3.22 Ensure that the /etc/sysconfig/docker file ownership is set to root:root (Manual) .......... 142
3.23 Ensure that the Containerd socket file ownership is set to root:root (Automated) ......... 144
3.24 Ensure that the Containerd socket file permissions are set to 660 or more restrictively
(Automated) ............................................................................................................................ 146
4 Container Images and Build File Configuration ............................................................. 148
4.1 Ensure that a user for the container has been created (Manual) ..................................... 149
4.2 Ensure that containers use only trusted base images (Manual) ...................................... 151
4.3 Ensure that unnecessary packages are not installed in the container (Manual) .............. 153
4.4 Ensure images are scanned and rebuilt to include security patches (Manual) ................ 155
4.5 Ensure Content trust for Docker is Enabled (Manual) ...................................................... 157
4.6 Ensure that HEALTHCHECK instructions have been added to container images (Manual)
............................................................................................................................................... 159
4.7 Ensure update instructions are not used alone in Dockerfiles (Manual) .......................... 161
4.8 Ensure setuid and setgid permissions are removed (Manual) ......................................... 163
4.9 Ensure that COPY is used instead of ADD in Dockerfiles (Manual) ................................ 165
4.10 Ensure secrets are not stored in Dockerfiles (Manual) .................................................. 167
4.11 Ensure only verified packages are installed (Manual) .................................................... 169
4.12 Ensure all signed artifacts are validated (Manual) ......................................................... 171
5 Container Runtime Configuration .................................................................................... 172
5.1 Ensure swarm mode is not Enabled, if not needed (Manual)........................................... 173
5.2 Ensure that, if applicable, an AppArmor Profile is enabled (Manual) ............................... 175
5.3 Ensure that, if applicable, SELinux security options are set (Manual) ............................. 177
5.4 Ensure that Linux kernel capabilities are restricted within containers (Manual) ............... 179
5.5 Ensure that privileged containers are not used (Manual) ................................................. 182
5.6 Ensure sensitive host system directories are not mounted on containers (Manual) ........ 184
5.7 Ensure sshd is not run within containers (Manual)........................................................... 186
5.8 Ensure privileged ports are not mapped within containers (Manual) ............................... 188
Page 4
Internal Only - General
5.9 Ensure that only needed ports are open on the container (Manual) ................................ 190
5.10 Ensure that the host's network namespace is not shared (Manual) ............................... 192
5.11 Ensure that the memory usage for containers is limited (Manual) ................................. 194
5.12 Ensure that CPU priority is set appropriately on containers (Manual)............................ 196
5.13 Ensure that the container's root filesystem is mounted as read only (Manual) .............. 198
5.14 Ensure that incoming container traffic is bound to a specific host interface (Manual).... 201
5.15 Ensure that the 'on-failure' container restart policy is set to '5' (Manual) ....................... 203
5.16 Ensure that the host's process namespace is not shared (Manual) ............................... 205
5.17 Ensure that the host's IPC namespace is not shared (Manual) ..................................... 207
5.18 Ensure that host devices are not directly exposed to containers (Manual) .................... 209
5.19 Ensure that the default ulimit is overwritten at runtime if needed (Manual).................... 211
5.20 Ensure mount propagation mode is not set to shared (Manual) .................................... 213
5.21 Ensure that the host's UTS namespace is not shared (Manual) .................................... 215
5.22 Ensure the default seccomp profile is not Disabled (Manual) ........................................ 217
5.23 Ensure that docker exec commands are not used with the privileged option (Manual) . 219
5.24 Ensure that docker exec commands are not used with the user=root option (Manual) . 221
5.25 Ensure that cgroup usage is confirmed (Manual)........................................................... 223
5.26 Ensure that the container is restricted from acquiring additional privileges (Manual) .... 225
5.27 Ensure that container health is checked at runtime (Manual) ........................................ 227
5.28 Ensure that Docker commands always make use of the latest version of their image
(Manual) ................................................................................................................................. 229
5.29 Ensure that the PIDs cgroup limit is used (Manual) ....................................................... 231
5.30 Ensure that Docker's default bridge "docker0" is not used (Manual) ............................. 233
5.31 Ensure that the host's user namespaces are not shared (Manual) ................................ 235
5.32 Ensure that the Docker socket is not mounted inside any containers (Manual)............. 237
6 Docker Security Operations ............................................................................................. 239
6.1 Ensure that image sprawl is avoided (Manual) ................................................................ 240
6.2 Ensure that container sprawl is avoided (Manual) ........................................................... 242
7 Docker Swarm Configuration ........................................................................................... 244
7.1 Ensure that the minimum number of manager nodes have been created in a swarm
(Manual) ................................................................................................................................. 245
7.2 Ensure that swarm services are bound to a specific host interface (Manual) .................. 247
7.3 Ensure that all Docker swarm overlay networks are encrypted (Manual) ........................ 249
7.4 Ensure that Docker's secret management commands are used for managing secrets in a
swarm cluster (Manual) .......................................................................................................... 251
7.5 Ensure that swarm manager is run in auto-lock mode (Manual) ...................................... 253
7.6 Ensure that the swarm manager auto-lock key is rotated periodically (Manual) .............. 255
7.7 Ensure that node certificates are rotated as appropriate (Manual) .................................. 257
7.8 Ensure that CA certificates are rotated as appropriate (Manual) ..................................... 259
7.9 Ensure that management plane traffic is separated from data plane traffic (Manual) ...... 261
Appendix: Summary Table........................................................................................ 263
Appendix: CIS Controls v7 IG 1 Mapped Recommendations ................................ 272
Appendix: CIS Controls v7 IG 2 Mapped Recommendations ................................ 274
Appendix: CIS Controls v7 IG 3 Mapped Recommendations ................................ 277
Appendix: CIS Controls v7 Unmapped Recommendations ................................... 281
Appendix: CIS Controls v8 IG 1 Mapped Recommendations ................................ 282
Appendix: CIS Controls v8 IG 2 Mapped Recommendations ................................ 285
Appendix: CIS Controls v8 IG 3 Mapped Recommendations ................................ 290
Page 5
Internal Only - General
Appendix: CIS Controls v8 Unmapped Recommendations ................................... 295
Appendix: Change History ........................................................................................ 296
Page 6
Internal Only - General
Overview
All CIS Benchmarks™ (Benchmarks) focus on technical configuration settings used to
maintain and/or increase the security of the addressed technology, and they should be
used in conjunction with other essential cyber hygiene tasks like:
• Monitoring the base operating system and applications for vulnerabilities and
quickly updating with the latest security patches.
• End-point protection (Antivirus software, Endpoint Detection and Response
(EDR), etc.).
• Logging and monitoring user and system activity.
In the end, the Benchmarks are designed to be a key component of a comprehensive
cybersecurity program.
Important Usage Information
All Benchmarks are available free for non-commercial use from the CIS Website. They
can be used to manually assess and remediate systems and applications. In lieu of
manual assessment and remediation, there are several tools available to assist with
assessment:
• CIS Configuration Assessment Tool (CIS-CAT® Pro Assessor)
• CIS Benchmarks™ Certified 3rd Party Tooling
These tools make the hardening process much more scalable for large numbers of
systems and applications.
NOTE: Some tooling focuses only on the Benchmark Recommendations that can
be fully automated (skipping ones marked Manual). It is important that ALL
Recommendations (Automated and Manual) be addressed since all are
important for properly securing systems and are typically in scope for
audits.
Key Stakeholders
Cybersecurity is a collaborative effort, and cross functional cooperation is imperative
within an organization to discuss, test, and deploy Benchmarks in an effective and
efficient way. The Benchmarks are developed to be best practice configuration
guidelines applicable to a wide range of use cases. In some organizations, exceptions
to specific Recommendations will be needed, and this team should work to prioritize the
problematic Recommendations based on several factors like risk, time, cost, and labor.
These exceptions should be properly categorized and documented for auditing
purposes.
Page 7
Internal Only - General
Apply the Correct Version of a Benchmark
Benchmarks are developed and tested for a specific set of products and versions and
applying an incorrect Benchmark to a system can cause the resulting pass/fail score to
be incorrect. This is due to the assessment of settings that do not apply to the target
systems. To assure the correct Benchmark is being assessed:
• Deploy the Benchmark applicable to the way settings are managed in the
environment: An example of this is the Microsoft Windows family of
Benchmarks, which have separate Benchmarks for Group Policy, Intune, and
Stand-alone systems based upon how system management is deployed.
Applying the wrong Benchmark in this case will give invalid results.
• Use the most recent version of a Benchmark: This is true for all Benchmarks,
but especially true for cloud technologies. Cloud technologies change frequently
and using an older version of a Benchmark may have invalid methods for
auditing and remediation.
Exceptions
The guidance items in the Benchmarks are called recommendations and not
requirements, and exceptions to some of them are expected and acceptable. The
Benchmarks strive to be a secure baseline, or starting point, for a specific technology,
with known issues identified during Benchmark development are documented in the
Impact section of each Recommendation. In addition, organizational, system specific
requirements, or local site policy may require changes as well, or an exception to a
Recommendation or group of Recommendations (e.g. A Benchmark could Recommend
that a Web server not be installed on the system, but if a system's primary purpose is to
function as a Webserver, there should be a documented exception to this
Recommendation for that specific server).
In the end, exceptions to some Benchmark Recommendations are common and
acceptable, and should be handled as follows:
• The reasons for the exception should be reviewed cross-functionally and be well
documented for audit purposes.
• A plan should be developed for mitigating, or eliminating, the exception in the
future, if applicable.
• If the organization decides to accept the risk of this exception (not work toward
mitigation or elimination), this should be documented for audit purposes.
It is the responsibility of the organization to determine their overall security policy, and
which settings are applicable to their unique needs based on the overall risk profile for
the organization.
Page 8
Internal Only - General
Remediation
CIS has developed Build Kits for many technologies to assist in the automation of
hardening systems. Build Kits are designed to correspond to Benchmark's
“Remediation” section, which provides the manual remediation steps necessary to make
that Recommendation compliant to the Benchmark.
When remediating systems (changing configuration settings on
deployed systems as per the Benchmark's Recommendations),
please approach this with caution and test thoroughly.
The following is a reasonable remediation approach to follow:
• CIS Build Kits, or internally developed remediation methods should never be
applied to production systems without proper testing.
• Proper testing consists of the following:
o Understand the configuration (including installed applications) of the targeted
systems. Various parts of the organization may need different configurations
(e.g., software developers vs standard office workers).
o Read the Impact section of the given Recommendation to help determine if
there might be an issue with the targeted systems.
o Test the configuration changes with representative lab system(s). If issues
arise during testing, they can be resolved prior to deploying to any production
systems.
o When testing is complete, initially deploy to a small sub-set of production
systems and monitor closely for issues. If there are issues, they can be
resolved prior to deploying more broadly.
o When the initial deployment above is completes successfully, iteratively
deploy to additional systems and monitor closely for issues. Repeat this
process until the full deployment is complete.
Summary
Using the Benchmarks Certified tools, working as a team with key stakeholders, being
selective with exceptions, and being careful with remediation deployment, it is possible
to harden large numbers of deployed systems in a cost effective, efficient, and safe
manner.
NOTE: As previously stated, the PDF versions of the CIS Benchmarks™ are
available for free, non-commercial use on the CIS Website. All other formats
of the CIS Benchmarks™ (MS Word, Excel, and Build Kits) are available for
CIS SecureSuite® members.
CIS-CAT® Pro is also available to CIS SecureSuite® members.
Page 9
Internal Only - General
Target Technology Details
This document, CIS Docker Benchmark, provides prescriptive guidance for establishing
a secure configuration posture for Docker Engine vNext This guide was tested against
Docker Engine Next on RHEL 7 and Ubuntu 20.04. To obtain the latest version of this
guide, please visit http://benchmarks.cisecurity.org. If you have questions, comments, or
have identified ways to improve this guide, please write us at [email protected].
Intended Audience
This document is intended for system and application administrators, security
specialists, auditors, help desk, and platform deployment personnel who plan to
develop, deploy, assess, or secure solutions that incorporate Docker Engine 26.1 or
later technology on Linux based platforms.
Page 10
Internal Only - General
Consensus Guidance
This CIS Benchmark™ was created using a consensus review process comprised of a
global community of subject matter experts. The process combines real world
experience with data-based information to create technology specific guidance to assist
users to secure their environments. Consensus participants provide perspective from a
diverse set of backgrounds including consulting, software development, audit and
compliance, security research, operations, government, and legal.
Each CIS Benchmark undergoes two phases of consensus review. The first phase
occurs during initial Benchmark development. During this phase, subject matter experts
convene to discuss, create, and test working drafts of the Benchmark. This discussion
occurs until consensus has been reached on Benchmark recommendations. The
second phase begins after the Benchmark has been published. During this phase, all
feedback provided by the Internet community is reviewed by the consensus team for
incorporation in the Benchmark. If you are interested in participating in the consensus
process, please visit https://workbench.cisecurity.org/.
Page 11
Internal Only - General
Typographical Conventions
The following typographical conventions are used throughout this guide:
Convention Meaning
Used for blocks of code, command, and
Stylized Monospace font script examples. Text should be interpreted
exactly as presented.
Used for inline code, commands, UI/Menu
Monospace font selections or examples. Text should be
interpreted exactly as presented.
Text set in angle brackets denote a variable
<Monospace font in brackets>
requiring substitution for a real value.
Used to reference other relevant settings,
CIS Benchmarks and/or Benchmark
Italic font
Communities. Also, used to denote the title
of a book, article, or other publication.
Additional information or caveats things like
Notes, Warnings, or Cautions (usually just
Bold font
the word itself and the rest of the text
normal).
Page 12
Internal Only - General
Recommendation Definitions
The following defines the various components included in a CIS recommendation as
applicable. If any of the components are not applicable it will be noted, or the
component will not be included in the recommendation.
Title
Concise description for the recommendation's intended configuration.
Assessment Status
An assessment status is included for every recommendation. The assessment status
indicates whether the given recommendation can be automated or requires manual
steps to implement. Both statuses are equally important and are determined and
supported as defined below:
Automated
Represents recommendations for which assessment of a technical control can be fully
automated and validated to a pass/fail state. Recommendations will include the
necessary information to implement automation.
Manual
Represents recommendations for which assessment of a technical control cannot be
fully automated and requires all or some manual steps to validate that the configured
state is set as expected. The expected state can vary depending on the environment.
Profile
A collection of recommendations for securing a technology or a supporting platform.
Most benchmarks include at least a Level 1 and Level 2 Profile. Level 2 extends Level 1
recommendations and is not a standalone profile. The Profile Definitions section in the
benchmark provides the definitions as they pertain to the recommendations included for
the technology.
Description
Detailed information pertaining to the setting with which the recommendation is
concerned. In some cases, the description will include the recommended value.
Rationale Statement
Detailed reasoning for the recommendation to provide the user a clear and concise
understanding on the importance of the recommendation.
Page 13
Internal Only - General
Impact Statement
Any security, functionality, or operational consequences that can result from following
the recommendation.
Audit Procedure
Systematic instructions for determining if the target system complies with the
recommendation.
Remediation Procedure
Systematic instructions for applying recommendations to the target system to bring it
into compliance according to the recommendation.
Default Value
Default value for the given setting in this recommendation, if known. If not known, either
not configured or not defined will be applied.
References
Additional documentation relative to the recommendation.
CIS Critical Security Controls® (CIS Controls®)
The mapping between a recommendation and the CIS Controls is organized by CIS
Controls version, Safeguard, and Implementation Group (IG). The Benchmark in its
entirety addresses the CIS Controls safeguards of (v7) “5.1 - Establish Secure
Configurations” and (v8) '4.1 - Establish and Maintain a Secure Configuration Process”
so individual recommendations will not be mapped to these safeguards.
Additional Information
Supplementary information that does not correspond to any other field but may be
useful to the user.
Page 14
Internal Only - General
Profile Definitions
The following configuration profiles are defined by this Benchmark:
• Level 1 - Docker - Linux
Items in this profile intend to:
o Be practical and prudent;
o Provide a clear security benefit; and
o Not inhibit the utility of the technology beyond acceptable means.
• Level 2 - Docker - Linux
Items in this profile exhibit one or more of the following characteristics:
o Are intended for environments or use cases where security is paramount
o Acts as defense in depth measure
o May negatively inhibit the utility or performance of the technology
• Level 1 - Docker Swarm
For use if Docker Swarm will be enabled
Page 15
Internal Only - General
Acknowledgements
This Benchmark exemplifies the great things a community of users, vendors, and
subject matter experts can accomplish through consensus collaboration. The CIS
community thanks the entire consensus team with special recognition to the following
individuals who contributed greatly to the creation of this guide:
Author
Pravin Goyal
Editors
Randall Mowen
Tony Wilwerding
Contributors
Thomas Sjögren https://github.com/konstruktoid
Jordan Rakoske GSEC, GCWN
Rory McCune
Brian Andrzejewski
Andrew Weiss
Ryan Puffer
Marion McCune
Joshua Lochner
Matthew Reagan
Page 16
Internal Only - General
Recommendations
1 Host Configuration
This section covers security recommendations that you should follow to prepare the
host machine that you plan to use for executing containerized workloads. Securing the
Docker host and following your infrastructure security best practices would build a solid
and secure foundation for executing containerized workloads.
Page 17
Internal Only - General
1.1 Linux Hosts Specific Configuration
This section contains recommendations that securing Linux Hosts running Docker
Containers.
Page 18
Internal Only - General
1.1.1 Ensure a separate partition for containers has been created
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
All Docker containers and their data and metadata is stored under /var/lib/docker
directory. By default, /var/lib/docker should be mounted under either the / or /var
partitions dependent on how the Linux operating system in use is configured.
Rationale:
Docker depends on /var/lib/docker as the default directory where all Docker related
files, including the images, are stored. This directory could fill up quickly causing both
Docker and the host to become unusable. For this reason, you should create a separate
partition (logical volume) for storing Docker files.
Impact:
None.
Audit:
At the Docker host execute one of the below commands:
grep '/var/lib/docker\s' /proc/mounts
This should return the partition details for the /var/lib/docker mountpoint.
mountpoint -- "$(docker info -f '{{ .DockerRootDir }}')"
This should return whether the configured root directory is a mount point.
Remediation:
For new installations, you should create a separate partition for the /var/lib/docker
mount point. For systems which have already been installed, you should use the Logical
Volume Manager (LVM) within Linux to create a new partition.
Default Value:
By default, /var/lib/docker is mounted under the / or /var partitions dependent on
how the OS is configured.
References:
1. https://www.projectatomic.io/docs/docker-storage-recommendation/
2. https://docs.docker.com/storage/
Page 19
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.12 Segment Data Processing and Storage Based on
Sensitivity
v8 Segment data processing and storage based on the sensitivity of the data. ● ●
Do not process sensitive data on enterprise assets intended for lower sensitivity
data.
v7 14 Controlled Access Based on the Need to Know
Controlled Access Based on the Need to Know
Page 20
Internal Only - General
1.1.2 Ensure only trusted users are allowed to control Docker
daemon (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The Docker daemon currently requires access to the Docker socket which is, by default,
owned by the user root and the group docker.
Rationale:
Docker allows you to share a directory between the Docker host and a guest container
without limiting the access rights of the container. This means that you can start a
container and map the / directory on your host to the container. The container would
then be able to modify your host file system without any restrictions. This means that
you could gain elevated privileges simply by being a member of the docker group and
subsequently start a container which maps the root / directory on the host.
Impact:
Provided the proceeding instructions are implemented, rights to build and execute
containers as normal user would be restricted.
Audit:
Execute the following command on the docker host and ensure that only trusted users
are members of the docker group.
getent group docker
Remediation:
You should remove any untrusted users from the docker group. Additionally, you
should not create a mapping of sensitive directories from the host to container volumes.
Default Value:
Not Applicable
References:
1. https://docs.docker.com/engine/security/#docker-daemon-attack-surface
2. http://www.projectatomic.io/blog/2015/08/why-we-dont-let-non-root-users-run-
docker-in-centos-fedora-or-rhel/
Page 21
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
6.1 Establish an Access Granting Process
v8 Establish and follow a process, preferably automated, for granting access to ● ● ●
enterprise assets upon new hire, rights grant, or role change of a user.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 22
Internal Only - General
1.1.3 Ensure auditing is configured for the Docker daemon
(Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Audit all Docker daemon activities.
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
the Docker daemon. Because this daemon runs with root privileges. It is very important
to audit its activities and usage.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
Verify that there are audit rules for the Docker daemon. For example, you could execute
the following command:
auditctl -l | grep /usr/bin/dockerd
This should show the rules associated with the Docker daemon.
Remediation:
You should add rules for the Docker daemon.
For example:
Add the line below to the /etc/audit/rules.d/audit.rules file:
-w /usr/bin/dockerd -k docker
Then, restart the audit daemon using the following command
systemctl restart auditd
Default Value:
By default, the Docker daemon is not audited.
Page 23
Internal Only - General
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.2 Collect Audit Logs
v8 Collect audit logs. Ensure that logging, per the enterprise’s audit log ● ● ●
management process, has been enabled across enterprise assets.
6.2 Activate audit logging
v7 Ensure that local logging has been enabled on all systems and networking ● ● ●
devices.
6.3 Enable Detailed Logging
Enable system logging to include detailed information such as an event
v7 source, date, user, timestamp, source addresses, destination addresses, and
● ●
other useful elements.
Page 24
Internal Only - General
1.1.4 Ensure auditing is configured for Docker files and directories
- /run/containerd (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Audit /run/containerd.
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
all Docker related files and directories. The Docker daemon runs with root privileges
and its behaviour depends on some key files and directories. /run/containerd is one
such directory. As it holds all the information about containers it should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule applied to the /run/containerd directory.
For example, you could execute the command below:
auditctl -l | grep /run/containerd
This should list a rule for the /run/containerd directory.
Remediation:
You should add a rule for the /run/containerd directory.
For example,
Add the line as below to the /etc/audit/rules.d/audit.rules file:
-a exit,always -F path=/run/containerd -F perm=war -k docker
Then, restart the audit daemon using the following command
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited.
Page 25
Internal Only - General
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 26
Internal Only - General
1.1.5 Ensure auditing is configured for Docker files and directories
- /var/lib/docker (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Audit /var/lib/docker or data-root.
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
all Docker related files and directories. The Docker daemon runs with root privileges
and its behaviour depends on some key files and directories. /var/lib/docker is one
such directory. As it holds all the information about containers it should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule applied to the /var/lib/docker directory
or whatever your data-root directory is set to.
You can configure the Docker daemon to use a different directory, using the data-root
configuration option. For example:
{
"data-root"; "/mnt/docker-data"
}
To perform an audit execute the command below:
auditctl -l | grep /var/lib/docker
or
auditctl -l | grep data-root
This should list a rule for the /var/lib/docker directory.
Remediation:
You should add a rule for the /var/lib/docker directory.
Adding exclusions for /var/lib/docker/overlay2 & /var/lib/docker/volumes reduces the
audit messages to a more manageable level.
For example,
Add the line as below to the /etc/audit/rules.d/audit.rules file:
Page 27
Internal Only - General
-a exit,always -F path=/var/lib/docker -F perm=war -k docker
-a exit,never -F dir=/var/lib/docker/volumes
-a exit,never -F dir=/var/lib/docker/overlay2
or for systems with namespace-remapping enabled
-a exit,always -F path=/var/lib/docker -F perm=war -k docker
-a exit,never -F dir=/var/lib/docker/165536.165536/volumes
-a exit,never -F dir=/var/lib/docker/165536.165536/overlay2
Then, restart the audit daemon using the following command
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
2. https://docs.docker.com/engine/daemon/#daemon-data-directory
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 28
Internal Only - General
1.1.6 Ensure auditing is configured for Docker files and directories
- /etc/docker (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Audit /etc/docker.
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
all Docker related files and directories. The Docker daemon runs with root privilege and
its behavior depends on some key files and directories, one of these being
/etc/docker. This holds various certificates and keys used for TLS communication
between Docker daemon and Docker client and as such it should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule applied to the /etc/docker directory.
For example, you could execute the command below:
auditctl -l | grep /etc/docker
This should display a rule for the /etc/docker directory.
Remediation:
You should add a rule for the /etc/docker directory.
For example:
Add the line below to the /etc/audit/rules.d/audit.rules file:
-w /etc/docker -k docker
Then restart the audit daemon. For example:
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited.
Page 29
Internal Only - General
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 30
Internal Only - General
1.1.7 Ensure auditing is configured for Docker files and directories
- docker.service (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit the docker.service if applicable.
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
all Docker related files and directories. The Docker daemon runs with root privileges
and its behavior depends on some key files and directories with docker.service being
one such file. The docker.service file might be present if the daemon parameters
have been changed by an administrator. If so, it holds various parameters for the
Docker daemon and should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
Step 1: Find out the file location:
systemctl show -p FragmentPath docker.service
Step 2: If the file does not exist, this recommendation does not apply. If the file does
exist, verify that there is an audit rule corresponding to the file:
For example, you could execute the command below:
auditctl -l | grep docker.service
This should display a rule for docker.service.
Remediation:
If the file exists, a rule for it should be added.
For example:
Add the line as below in /etc/audit/rules.d/audit.rules file:
-w /usr/lib/systemd/system/docker.service -k docker
Then restart the audit daemon.
For example:
Page 31
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file
docker.service may not be present on the system.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 32
Internal Only - General
1.1.8 Ensure auditing is configured for Docker files and directories
- containerd.sock (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit containerd.sock, if applicable.
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
the Docker daemon. Because this daemon runs with root privileges, it is very important
to audit its activities and usage. Its behavior depends on some key files and directories
with containerd.sock being one such file, and as this holds various parameters for the
Docker daemon, it should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
Step 1: Find out the file location:
grep 'containerd.sock' /etc/containerd/config.toml
or by checking the Docker --containerd option.
Step 2: If the file does not exist, this recommendation is not applicable. If the file exists,
you should verify that there is an audit rule corresponding to the file:
For example, you could execute the command below:
auditctl -l | grep containerd.sock
This should display a rule for containerd.sock.
Remediation:
If the file exists, you should add a rule for it.
For example:
Add the line below to the /etc/audit/rules.d/audit.rules file:
-w /run/containerd/containerd.sock -k docker
Then restart the audit daemon.
For example:
Page 33
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file
containerd.sock may not be present, but if it is, it should be audited.
References:
1. https://github.com/containerd/containerd/blob/master/docs/ops.md
2. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
3. https://docs.docker.com/engine/reference/commandline/dockerd/#docker-
runtime-execution-options
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 34
Internal Only - General
1.1.9 Ensure auditing is configured for Docker files and directories
- docker.sock (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit docker.sock, if applicable.
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
the Docker daemon. Because this daemon runs with root privileges, it is very important
to audit its activities and usage. Its behavior depends on some key files and directories
with docker.socket being one such file, and as this holds various parameters for the
Docker daemon, it should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
Step 1: Find out the configuration file location:
systemctl show -p FragmentPath docker.sock
Step 2: Locate the socket file location:
grep ListenStream <FragmentPath from previous step>
Step 3: If the file does not exist, this recommendation is not applicable. If the file exists,
you should verify that there is an audit rule corresponding to the file:
For example, you could execute the command below:
auditctl -l | grep docker.sock
This should display a rule for docker.sock.
Remediation:
If the file exists, you should add a rule for it.
For example:
Add the line below to the /etc/audit/rules.d/audit.rules file:
-w /var/run/docker.sock -k docker
Then restart the audit daemon.
For example:
Page 35
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file docker.sock
may not be present, but if it is, it should be audited.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 36
Internal Only - General
1.1.10 Ensure auditing is configured for Docker files and
directories - /etc/default/docker (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit /etc/default/docker, if applicable.
Rationale:
As well as auditing the normal Linux file system and system calls, you should audit all
Docker related files and directories. The Docker daemon runs with root privileges and
its behavior depends on some key files and directories. /etc/default/docker is one
such file. It holds various parameters related to the Docker daemon and should
therefore be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule associated with the /etc/default/docker
file.
For example, you could execute the command below:
auditctl -l | grep /etc/default/docker
This should display a rule for the /etc/default/docker file.
Remediation:
You should add a rule for the /etc/default/docker file.
For example:
Add the line below to the /etc/audit/audit.rules file:
-w /etc/default/docker -k docker
Then restart the audit daemon.
For example:
Page 37
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited so these defaults should
be changed in line with organizational security policy. The file /etc/default/docker
may not be present, and if so, this recommendation is not applicable.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 38
Internal Only - General
1.1.11 Ensure auditing is configured for Docker files and
directories - /etc/docker/daemon.json (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit /etc/docker/daemon.json, if applicable.
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
all Docker related files and directories. The Docker daemon runs with root privileges
and its behavior depends on some key files and directories.
/etc/docker/daemon.json is one such file. This holds various parameters for the
Docker daemon, and as such it should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule associated with the
/etc/docker/daemon.json file.
For example, you could execute the command below:
auditctl -l | grep /etc/docker/daemon.json
This should display a rule for the /etc/docker/daemon.json file.
Remediation:
You should add a rule for the /etc/docker/daemon.json file.
For example:
Add the line below to the /etc/audit/audit.rules file:
-w /etc/docker/daemon.json -k docker
Then restart the audit daemon.
For example:
Page 39
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file
/etc/docker/daemon.json may not exist on the system and in that case, this
recommendation is not applicable.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
2. https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-
configuration-file
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 40
Internal Only - General
1.1.12 Ensure auditing is configured for Docker files and
directories - /etc/containerd/config.toml (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit /etc/containerd/config.toml if applicable
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
the Docker daemon. Because this daemon runs with root privileges it is very important
to audit its activities and usage. Its behavior depends on some key files and directories
and /etc/containerd/config.toml is one such file as it contains various parameters.
If present, it is important that it is audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule present relating to the
/etc/containerd/config.toml file.
For example, you could execute the command below:
auditctl -l | grep /etc/containerd/config.toml
This should display a rule for /etc/containerd/config.toml file.
Remediation:
You should add a rule for /etc/containerd/config.toml file.
For example:
Add the line below to the /etc/audit/audit.rules file:
-w /etc/containerd/config.toml -k docker
Then restart the audit daemon.
For example:
Page 41
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file
/etc/containerd/config.toml may not be present on the system and in that case,
this recommendation is not applicable.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 42
Internal Only - General
1.1.13 Ensure auditing is configured for Docker files and
directories - /etc/sysconfig/docker (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit /etc/sysconfig/docker if applicable
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
the Docker daemon. Because this daemon runs with root privileges it is very important
to audit its activities and usage. Its behavior depends on some key files and directories
and /etc/sysconfig/docker is one such file as it contains various parameters related
to the Docker daemon when run on CentOS and RHEL based distributions. If present, it
is important that it is audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule present relating to the
/etc/sysconfig/docker file.
For example, you could execute the command below:
auditctl -l | grep /etc/sysconfig/docker
This should display a rule for /etc/sysconfig/docker file.
Remediation:
You should add a rule for /etc/sysconfig/docker file.
For example:
Add the line below to the /etc/audit/audit.rules file:
-w /etc/sysconfig/docker -k docker
Then restart the audit daemon.
For example:
Page 43
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file
/etc/sysconfig/docker may not be presemt on the system and in that case, this
recommendation is not applicable.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 44
Internal Only - General
1.1.14 Ensure auditing is configured for Docker files and
directories - /usr/bin/containerd (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit /usr/bin/containerd if applicable.
Rationale:
As well as auditing the normal Linux file system and system calls, you should audit all
Docker related files and directories. The Docker daemon runs with root privileges and
its behavior depends on some key files and directories. /usr/bin/containerd is one
such file and as such should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule corresponding to /usr/bin/containerd
file.
For example, you could execute the command below:
auditctl -l | grep /usr/bin/containerd
This should display a rule for /usr/bin/containerd file.
Remediation:
You should add a rule for the /usr/bin/containerd file.
For example:
Add the line below to the /etc/audit/audit.rules file:
-w /usr/bin/containerd -k docker
Then restart the audit daemon.
For example:
Page 45
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file
/usr/bin/containerd may not be present on the system and in that case, this
recommendation is not applicable.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
2. https://containerd.io/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 46
Internal Only - General
1.1.15 Ensure auditing is configured for Docker files and
directories - /usr/bin/containerd-shim (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit /usr/bin/containerd-shim if applicable.
Rationale:
As well as auditing the normal Linux file system and system calls, you should audit all
Docker related files and directories. The Docker daemon runs with root privileges and
its behavior depends on some key files and directories. /usr/bin/containerd-shim is
one such file and as such should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule corresponding to /usr/bin/containerd-
shim file.
For example, you could execute the command below:
auditctl -l | grep /usr/bin/containerd-shim
This should display a rule for /usr/bin/containerd-shim file.
Remediation:
You should add a rule for the /usr/bin/containerd-shim file.
For example:
Add the line below to the /etc/audit/rules.d/audit.rules file:
-w /usr/bin/containerd-shim -k docker
Then restart the audit daemon.
For example:
Page 47
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file
/usr/bin/containerd-shim may not be present on the system and in that case, this
recommendation is not applicable.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
2. https://containerd.io/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 48
Internal Only - General
1.1.16 Ensure auditing is configured for Docker files and
directories - /usr/bin/containerd-shim-runc-v1 (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit /usr/bin/containerd-shim-runc-v1 if applicable.
Rationale:
As well as auditing the normal Linux file system and system calls, you should audit all
Docker related files and directories. The Docker daemon runs with root privileges and
its behavior depends on some key files and directories. /usr/bin/containerd-shim-
runc-v1 is one such file and as such should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule corresponding to /usr/bin/containerd-
shim-runc-v1 file.
For example, you could execute the command below:
auditctl -l | grep /usr/bin/containerd-shim-runc-v1
This should display a rule for /usr/bin/containerd-shim-runc-v1 file.
Remediation:
You should add a rule for the /usr/bin/containerd-shim-runc-v1 file.
For example:
Add the line below to the /etc/audit/audit.rules file:
-w /usr/bin/containerd-shim-runc-v1 -k docker
Then restart the audit daemon.
For example:
Page 49
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file
/usr/bin/containerd-shim-runc-v1 may not be present on the system and in that
case, this recommendation is not applicable.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
2. https://containerd.io/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 50
Internal Only - General
1.1.17 Ensure auditing is configured for Docker files and
directories - /usr/bin/containerd-shim-runc-v2 (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit /usr/bin/containerd-shim-runc-v2 if applicable.
Rationale:
As well as auditing the normal Linux file system and system calls, you should audit all
Docker related files and directories. The Docker daemon runs with root privileges and
its behavior depends on some key files and directories. /usr/bin/containerd-shim-
runc-v2 is one such file and as such should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule corresponding to /usr/bin/containerd-
shim-runc-v2 file.
For example, you could execute the command below:
auditctl -l | grep /usr/bin/containerd-shim-runc-v2
This should display a rule for /usr/bin/containerd-shim-runc-v2 file.
Remediation:
You should add a rule for the /usr/bin/containerd-shim-runc-v2 file.
For example:
Add the line below to the /etc/audit/audit.rules file:
-w /usr/bin/containerd-shim-runc-v2 -k docker
Then restart the audit daemon.
For example:
Page 51
Internal Only - General
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file
/usr/bin/containerd-shim-runc-v2 may not be present on the system and in that
case, this recommendation is not applicable.
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
2. https://containerd.io/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 52
Internal Only - General
1.1.18 Ensure auditing is configured for Docker files and
directories - /usr/bin/runc (Automated)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Audit /usr/bin/runc if applicable
Rationale:
As well as auditing the normal Linux file system and system calls, you should also audit
all Docker related files and directories. The Docker daemon runs with root privileges
and its behavior depends on some key files and directories. /usr/bin/runc is one
such file, and as such it should be audited.
Impact:
Auditing can generate large log files. You should ensure that these are rotated and
archived periodically. A separate partition should also be created for audit logs to avoid
filling up any other critical partition.
Audit:
You should verify that there is an audit rule corresponding to /usr/bin/runc file.
For example, you could execute the command below:
auditctl -l | grep /usr/bin/runc
This should display a rule for the /usr/bin/runc file.
Remediation:
You should add a rule for /usr/bin/runc file.
For example:
Add the line below to the /etc/audit/audit.rules file:
-w /usr/bin/runc -k docker
Then restart the audit daemon.
For example:
systemctl restart auditd
Default Value:
By default, Docker related files and directories are not audited. The file /usr/bin/runc
may not be present on the system and in that case this recommendation is not
applicable.
Page 53
Internal Only - General
References:
1. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux/8/html/system_design_guide/auditing-the-
system_system-design-guide
2. https://containerd.io
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
14.9 Enforce Detail Logging for Access or Changes to
Sensitive Data
v7 Enforce detailed audit logging for access to sensitive data or changes to ●
sensitive data (utilizing tools such as File Integrity Monitoring or Security
Information and Event Monitoring).
Page 54
Internal Only - General
1.2 General Configuration
This section contains general host recommendations for systems running Docker
Page 55
Internal Only - General
1.2.1 Ensure the container host has been Hardened (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
A container host is able to run one or more containers. It is of utmost importance to
harden the host to mitigate host security misconfiguration.
Rationale:
You should follow infrastructure security best practices and harden your host OS.
Keeping the host system hardened will ensure that host vulnerabilities are mitigated.
Not hardening the host system could lead to security exposures and breaches.
Impact:
None.
Audit:
Ensure that the host specific security guidelines are followed. Ask the system
administrators which security benchmark the current host system should currently be
compliant with and check that security standards associated with this standard are
currently in place.
Remediation:
You may consider various CIS Security Benchmarks for your container host. If you have
other security guidelines or regulatory requirements to adhere to, please follow them as
suitable in your environment.
Default Value:
By default, the host has factory setting and is not hardened.
References:
1. https://docs.docker.com/engine/security/
2. https://www.cisecurity.org/cis-benchmarks/
Page 56
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.7 Use Standard Hardening Configuration Templates for
Application Infrastructure
Use standard, industry-recommended hardening configuration templates for
v8 application infrastructure components. This includes underlying servers, databases, ● ●
and web servers, and applies to cloud containers, Platform as a Service (PaaS)
components, and SaaS components. Do not allow in-house developed software to
weaken configuration hardening.
5 Secure Configuration for Hardware and Software on
v7 Mobile Devices, Laptops, Workstations and Servers
Secure Configuration for Hardware and Software on Mobile Devices, Laptops,
Workstations and Servers
Page 57
Internal Only - General
1.2.2 Ensure that the version of Docker is up to date (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Frequent releases for Docker are issued which address security vulnerabilities, resolve
product bugs and bring in new functionality. You should keep a tab on these product
updates and upgrade as frequently as possible in line with the general IT security policy
of your organization.
Rationale:
By staying up to date on Docker updates, vulnerabilities in the software can be
mitigated. An experienced attacker may be able to exploit known vulnerabilities resulting
in them being able to attain inappropriate access or to elevate their privileges. If you do
not ensure that Docker is running at the most current release consistent with the
requirements of of your application, you may introduce unwanted behaviour and it is
therefore important to ensure that you monitor software versions and upgrade in a
timely fashion.
Impact:
You should perform a risk assessment regarding Docker version updates and review
how they may impact your operations. You should be aware that third-party products
that use Docker may require older major versions of Docker to be supported, and this
should be reviewed in line with the general IT security policy of your organization,
particularly where security vulnerabilities in older versions have been publicly disclosed.
Audit:
You should execute the command below in order to verify that the Docker version is up
to date in line with the requirements of the application you are running. It should be
noted that it is not a security requirement to be at the most up to date version, provided
the version you are using does not contain any critical or high security vulnerabilities.
docker version
Remediation:
You should monitor versions of Docker releases and make sure your software is
updated as required.
Default Value:
Not Applicable
Page 58
Internal Only - General
References:
1. https://docs.docker.com/engine/install/
2. https://docs.docker.com/engine/release-notes/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.5 Use Up-to-Date and Trusted Third-Party Software
Components
v8 Use up-to-date and trusted third-party software components. When possible,
choose established and proven frameworks and libraries that provide adequate
● ●
security. Acquire these components from trusted sources or evaluate the software
for vulnerabilities before use.
v7 3 Continuous Vulnerability Management
Continuous Vulnerability Management
Page 59
Internal Only - General
2 Docker daemon configuration
This section lists the recommendations that alter and secure the behavior of the Docker
daemon. The settings that are under this section affect ALL container instances.
Note: Docker daemon options, when running in the default rootful mode, can also be
controlled using files such as /etc/sysconfig/docker, /etc/default/docker, the
systemd unit file or /etc/docker/daemon.json. Also, note that Docker in daemon
mode can be identified as /usr/bin/dockerd, or having -d or daemon as the argument
to docker service.
Note: When running in rootless mode does change all configuration file locations and
has some known limitations regarding e.g privileged TCP/UDP ports and specific
prerequisites depending on which distribution that is used.
Page 60
Internal Only - General
2.1 Run the Docker daemon as a non-root user, if possible
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Rootless mode executes the Docker daemon and containers inside a user namespace,
with both the daemon and the container are running without root privileges.
Rationale:
Rootless mode allows running the Docker daemon and containers as a non-root user to
mitigate potential vulnerabilities in the daemon and the container runtime.
Impact:
There are multiple prerequisites depending on which distribution that is in use, and also
known limitations regarding networking and resource limitation.
Running in rootless mode also changes the location of any configuration files in use,
including all containers using the daemon.
Audit:
Running the following command will show any running dockerd processes and which
user that is managing the daemon.
ps -fe | grep 'dockerd'
Remediation:
Follow the current Docker documentation on how to install the Docker daemon as a
non-root user.
Default Value:
The Docker daemon is running as the root user by default.
References:
1. https://docs.docker.com/engine/security/rootless/
Page 61
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.1 Establish and Maintain a Secure Configuration Process
Establish and maintain a secure configuration process for enterprise assets
(end-user devices, including portable and mobile, non-computing/IoT devices, and
v8 servers) and software (operating systems and applications). Review and update
● ● ●
documentation annually, or when significant enterprise changes occur that could
impact this Safeguard.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 62
Internal Only - General
2.2 Ensure network traffic is restricted between containers on the
default bridge (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
By default, all network traffic is allowed between containers on the same host on the
default network bridge. If not desired, restrict all inter-container communication. Link
specific containers together that require communication. Alternatively, you can create
custom network and only join containers that need to communicate to that custom
network.
Rationale:
By default, unrestricted network traffic is enabled between all containers on the same
host on the default network bridge. Thus, each container has the potential of reading all
packets across the container network on the same host. This might lead to an
unintended and unwanted disclosure of information to other containers. Hence, restrict
inter-container communication on the default network bridge.
Impact:
Inter-container communication would be disabled on the default network bridge. If any
communication between containers on the same host is desired, then it needs to be
explicitly defined using container linking or alternatively custom networks have to be
defined.
Audit:
Run the below command and verify that the default network bridge has been configured
to restrict inter-container communication.
docker network ls --quiet | xargs docker network inspect --format '{{ .Name
}}: {{ .Options }}'
It should return com.docker.network.bridge.enable_icc:false for the default
network bridge.
Remediation:
Edit the Docker daemon configuration file to ensure that icc is disabled. It should include
the following setting
"icc": false
Alernatively, run the docker daemon directly and pass --icc=false as an argument.
For Example,
Page 63
Internal Only - General
dockerd --icc=false
Alternatively, you can follow the Docker documentation and create a custom network
and only join containers that need to communicate to that custom network. The --icc
parameter only applies to the default docker bridge, if custom networks are used then
the approach of segmenting networks should be adopted instead.
In order for this control to be fully effective, all containers connected to the docker0
bridge should drop the NET_RAW capability, otherwise a compromised container could
use raw ethernet packets to communicate with other containers despite this restriction.
Default Value:
By default, all inter-container communication is allowed on the default network bridge.
References:
1. https://docs.docker.com/network/
2. https://github.com/docker/cli/blob/v20.10.1/man/dockerd.8.md
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
12.3 Securely Manage Network Infrastructure
Securely manage network infrastructure. Example implementations include
v8 version-controlled-infrastructure-as-code, and the use of secure network
● ●
protocols, such as SSH and HTTPS.
9 Limitation and Control of Network Ports, Protocols, and
v7 Services
Limitation and Control of Network Ports, Protocols, and Services
Page 64
Internal Only - General
2.3 Ensure the logging level is set to 'info' (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Set Docker daemon log level to info.
Rationale:
Setting up an appropriate log level, configures the Docker daemon to log events that
you would want to review later. A base log level of info and above would capture all
logs except debug logs. Until and unless required, you should not run Docker daemon
at debug log level.
Impact:
None.
Audit:
To confirm this setting a combination of reviewing the dockerd start-up options and a
review of any settings in /etc/docker/daemon.json should be completed.
To review the dockerd startup options, use:
grep "log-level" /etc/docker/daemon.json
Ensure that either the --log-level parameter is not present or if present, then it is set
to info.
The contents of /etc/docker/daemon.json should also be reviewed for this setting.
Remediation:
Ensure that the Docker daemon configuration file has the following configuration
included
"log-level": "info"
Alternatively, run the Docker daemon as below:
dockerd --log-level="info"
Default Value:
By default, Docker daemon is set to log level of info.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/
Page 65
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.5 Collect Detailed Audit Logs
Configure detailed audit logging for enterprise assets containing sensitive data.
v8 Include event source, date, username, timestamp, source addresses, destination
● ●
addresses, and other useful elements that could assist in a forensic investigation.
6.2 Activate audit logging
v7 Ensure that local logging has been enabled on all systems and networking ● ● ●
devices.
6.3 Enable Detailed Logging
Enable system logging to include detailed information such as an event source,
v7 date, user, timestamp, source addresses, destination addresses, and other useful
● ●
elements.
Page 66
Internal Only - General
2.4 Ensure Docker is allowed to make changes to iptables
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The iptables firewall is used to set up, maintain, and inspect the tables of IP packet filter
rules within the Linux kernel. The Docker daemon should be allowed to make changes
to the iptables ruleset.
Rationale:
Docker will never make changes to your system iptables rules unless you allow it to
do so. If you do allow this, Docker server will automatically make any required changes.
We recommended letting Docker make changes to iptables automatically in order to
avoid networking misconfigurations that could affect the communication between
containers and with the outside world. Additionally, this reduces the administrative
overhead of updating iptables every time you add containers or modify networking
options.
Impact:
The Docker daemon service requires iptables rules to be enabled before it starts. Any
restarts of iptables during Docker daemon operation may result in losing Docker created
rules. Adding iptables-persistent to your iptables install can assist with mitigation of this
impact.
Audit:
To confirm this setting you should review the dockerd start-up options and the settings
in /etc/docker/daemon.json
To review the dockerd startup options, use:
grep "--iptables" /etc/docker/daemon.json
Ensure that the --iptables parameter is either not present or not set to false.
The contents of /etc/docker/daemon.json should also be reviewed for this setting.
Remediation:
Do not run the Docker daemon with --iptables=false parameter. For example, do
not start the Docker daemon as below:
Page 67
Internal Only - General
dockerd --iptables=false
Default Value:
By default, iptables is set to true.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/
2. https://docs.docker.com/network/iptables/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
12.2 Establish and Maintain a Secure Network
Architecture
v8 Establish and maintain a secure network architecture. A secure network ● ●
architecture must address segmentation, least privilege, and availability, at a
minimum.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 68
Internal Only - General
2.5 Ensure insecure registries are not used (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Docker considers a private registry either secure or insecure. By default, registries are
considered secure.
Rationale:
A secure registry uses TLS. A copy of registry's CA certificate is placed on the Docker
host at /etc/docker/certs.d/<registry-name>/ directory. An insecure registry is
one which does not have a valid registry certificate, or one not using TLS. Insecure
registries should not be used as they present a risk of traffic interception and
modification.
Additionally, once a registry has been marked as insecure commands such as docker
pull, docker push, and docker search will not result in an error message and users
may indefinitely be working with this type of insecure registry without ever being notified
of the risk of potential compromise.
Impact:
None.
Audit:
You should execute the command below to find out if any insecure registries are in use:
docker info --format 'Insecure Registries:'
Remediation:
You should ensure that no insecure registries are in use.
Default Value:
By default, Docker assumes all, but local, registries are secure.
Additional Information:
Docker engine always include 127.0.0.0/8 and ::1/128 as insecure registers
Page 69
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
2.5 Allowlist Authorized Software
Use technical controls, such as application allowlisting, to ensure that only
v8 authorized software can execute or be accessed. Reassess bi-annually, or more
● ●
frequently.
v7 14.4 Encrypt All Sensitive Information in Transit ● ●
Encrypt all sensitive information in transit.
Page 70
Internal Only - General
2.6 Ensure aufs storage driver is not used (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Do not use aufs as the storage driver for your Docker instance.
Rationale:
The aufs storage driver is the oldest storage driver used on Linux systems. It is based
on a Linux kernel patch-set that is unlikely in future to be merged into the main OS
kernel. The aufs driver is also known to cause some serious kernel crashes. aufs only
has legacy support within systems using Docker.
Most importantly, aufs is not a supported driver in many Linux distributions using latest
Linux kernels and has also been deprecated with Docker Engine release 20.10.
Impact:
aufs is the only storage driver that allows containers to share executable and shared
library memory. It might be useful if you are running thousands of containers with the
same program or libraries, however its use should be reviewed in line with your
organization's security policy.
Audit:
Execute the below command and verify that aufs is not used as storage driver:
docker info --format 'Storage Driver: {{ .Driver }}'
The above command should not return aufs.
Remediation:
Do not explicitly use aufs as storage driver.
For example, do not start Docker daemon as below:
dockerd --storage-driver aufs
Default Value:
By default, Docker uses overlay2 as the storage driver on most of the platforms. The
default storage driver can vary based on your OS vendor. You should use the storage
driver that is recommended by your preferred vendor and which is in line with policy
around the applications which are being deployed.
References:
1. https://docs.docker.com/storage/storagedriver/aufs-driver/
Page 71
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16 Application Software Security
Manage the security life cycle of in-house developed, hosted, or acquired
v8 software to prevent, detect, and remediate security weaknesses before they can
impact the enterprise.
v7 18 Application Software Security
Application Software Security
Page 72
Internal Only - General
2.7 Ensure devicemapper storage driver is not used (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Do not use devicemapper as the storage driver for your Docker instance.
Rationale:
The devicemapper storage driver is deprecated in favor of overlay2, and has been
removed in Docker Engine v25.0.
Impact:
If you are using Device Mapper, you must migrate to a supported storage driver before
upgrading to Docker Engine v25.0.
Audit:
Execute the below command and verify that devicemapper is not used as storage
driver:
docker info --format 'Storage Driver: {{ .Driver }}'
The above command should not return devicemapper.
Remediation:
Do not explicitly use devicemapper as storage driver.
For example, do not start Docker daemon as below:
dockerd --storage-driver devicemapper
Default Value:
By default, Docker uses overlay2 as the storage driver on most of the platforms. The
default storage driver can vary based on your OS vendor. You should use the storage
driver that is recommended by your preferred vendor and which is in line with policy
around the applications which are being deployed.
References:
1. https://docs.docker.com/storage/storagedriver/select-storage-driver/
Page 73
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16 Application Software Security
Manage the security life cycle of in-house developed, hosted, or acquired
v8 software to prevent, detect, and remediate security weaknesses before they can
impact the enterprise.
v7 18 Application Software Security
Application Software Security
Page 74
Internal Only - General
2.8 Ensure TLS authentication for Docker daemon is configured
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
It is possible to make the Docker daemon available remotely over a TCP port. If this is
required, you should ensure that TLS authentication is configured in order to restrict
access to the Docker daemon via IP address and port.
Rationale:
By default, the Docker daemon binds to a non-networked Unix socket and runs with
root privileges. If you change the default Docker daemon binding to a TCP port or any
other Unix socket, anyone with access to that port or socket could have full access to
the Docker daemon and therefore in turn to the host system. For this reason, you
should not bind the Docker daemon to another IP/port or a Unix socket.
If you must expose the Docker daemon via a network socket, you should configure TLS
authentication for the daemon and for any Docker Swarm APIs (if they are in use). This
type of configuration restricts the connections to your Docker daemon over the network
to a limited number of clients who have access to the TLS client credentials.
Impact:
You would need to manage and guard certificates and keys for the Docker daemon and
Docker clients.
Audit:
To confirm this setting, review the dockerd start-up options and any settings in
/etc/docker/daemon.json.
To review the dockerd startup options, use:
grep "--tls" /etc/docker/daemon.json
Ensure that the below parameters are present:
--tlsverify
--tlscacert
--tlscert
--tlskey
The contents of /etc/docker/daemon.json to ensure these settings are in place.
Remediation:
Follow the steps mentioned in the Docker documentation or other references.
Page 75
Internal Only - General
Default Value:
By default, TLS authentication is not configured.
References:
1. https://docs.docker.com/engine/security/https/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
13.5 Manage Access Control for Remote Assets
Manage access control for assets remotely connecting to enterprise resources.
Determine amount of access to enterprise resources based on: up-to-date anti-
v8 malware software installed, configuration compliance with the enterprise’s secure
● ●
configuration process, and ensuring the operating system and applications are up-
to-date.
9.2 Ensure Only Approved Ports, Protocols and Services
v7 Are Running ● ●
Ensure that only network ports, protocols, and services listening on a system
with validated business needs, are running on each system.
Page 76
Internal Only - General
2.9 Ensure the default ulimit is configured appropriately (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Set the default ulimit options as appropriate in your environment.
Rationale:
ulimit provides control over the resources available to the shell and to processes
which it starts. Setting system resource limits judiciously can save you from disasters
such as a fork bomb. On occasion, even friendly users and legitimate processes can
overuse system resources and can make the system unusable.
Setting the default ulimit for the Docker daemon enforces the ulimit for all container
instances. In this case you would not need to setup ulimit for each container instance.
However, the default ulimit can be overridden during container runtime, if needed.
Therefore, in order to have proper control over system resources, define a default ulimit
as is needed in your environment.
Impact:
If ulimits are set incorrectly this could cause issues with system resources, possibly
causing a denial of service condition.
Audit:
To confirm this setting you should review the dockerd start-up options and any settings
in /etc/docker/daemon.json.
To review the dockerd startup options, use:
ps -ef | grep dockerd
Ensure that the --default-ulimit parameter is set as appropriate.
The contents of /etc/docker/daemon.json should also be reviewed for this setting.
Remediation:
Run Docker in daemon mode and pass --default-ulimit as argument with
respective ulimits as appropriate in your environment and in line with your security
policy.
For Example,
dockerd --default-ulimit nproc=1024:2048 --default-ulimit nofile=100:200
Default Value:
By default, no ulimit is set.
Page 77
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#default-ulimit-
settings
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.7 Use Standard Hardening Configuration Templates for
Application Infrastructure
Use standard, industry-recommended hardening configuration templates for
v8 application infrastructure components. This includes underlying servers, databases, ● ●
and web servers, and applies to cloud containers, Platform as a Service (PaaS)
components, and SaaS components. Do not allow in-house developed software to
weaken configuration hardening.
v7 18 Application Software Security
Application Software Security
Page 78
Internal Only - General
2.10 Enable user namespace support (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should enable user namespace support in Docker daemon to utilize container user
to host user re-mapping. This recommendation is beneficial where the containers you
are using do not have an explicit container user defined in the container image. If the
container images that you are using have a pre-defined non-root user, this
recommendation may be skipped as this feature is still in its infancy, and might result in
unpredictable issues or difficulty in configuration.
Rationale:
The Linux kernel "user namespace" support within the Docker daemon provides
additional security for the Docker host system. It allows a container to have a unique
range of user and group IDs which are outside the traditional user and group range
utilized by the host system.
For example, the root user can have the expected administrative privileges inside the
container but can effectively be mapped to an unprivileged UID on the host system.
Impact:
User namespace remapping is incompatible with a number of Docker features and also
currently breaks some of its functionalities. Reference the Docker documentation and
included links for details.
Audit:
docker inspect --format='{{ .State.Pid }}' $(docker ps -q) | while read -r
line; do ps -h -p "$line" -o pid,user; done
The above command will find the PID of the container and then list the host user
associated with the container process. If the container process is running as root, then
this configuration may be non-compliant with your organization's security policy.
Alternatively, you can run docker info to ensure that the userns is listed under
Security Options:
Page 79
Internal Only - General
docker info --format '{{ .SecurityOptions }}'
Remediation:
Please consult the Docker documentation for various ways in which this can be
configured depending upon your requirements. Your steps might also vary based on
platform - For example, on Red Hat, sub-UIDs and sub-GIDs mapping creation do not
work automatically. You might have to create your own mapping.
The high-level steps are as below:
Step 1: Ensure that the files /etc/subuid and /etc/subgid exist.
touch /etc/subuid /etc/subgid
Step 2: Start the docker daemon with --userns-remap flag
dockerd --userns-remap=default
Default Value:
By default, user namespace is not remapped. Consideration should be given to
implementing this in line with the requirements of the applications being used and the
organization's security policy.
References:
1. https://man7.org/linux/man-pages/man7/user_namespaces.7.html
2. https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-user-
namespace-options
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
6 Access Control Management
Use processes and tools to create, assign, manage, and revoke access
v8 credentials and privileges for user, administrator, and service accounts for
enterprise assets and software.
v7 18 Application Software Security
Application Software Security
Page 80
Internal Only - General
2.11 Ensure the default cgroup usage has been confirmed
(Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
The --cgroup-parent option allows you to set the default cgroup parent to use for all
containers. If there is no specific usage requirement for this, the setting should be left at
its default.
Rationale:
System administrators typically define cgroups under which containers are supposed to
run. Even if cgroups are not explicitly defined by the system administrators, containers
run under docker cgroup by default.
It is possible to attach to a different cgroup other than the one which is the default,
however this type of usage should be monitored and confirmed because attaching to a
different cgroup other than the one that is a default, it could be possible to share
resources unevenly causing resource utilization problems on the host.
Impact:
None.
Audit:
In order to confirm this setting, the dockerd start-up options and any settings in
/etc/docker/daemon.json should be reviewed.
To review the dockerd startup options, use:
grep "--cgroup-parent" /etc/docker/daemon.json
You should ensure that the --cgroup-parent parameter is either not set or is set as
appropriate non-default cgroup.
The contents of /etc/docker/daemon.json should also be checked for this setting.
Remediation:
The default setting is in line with good security practice and can be left in situ. If you
wish to specifically set a non-default cgroup, pass the --cgroup-parent parameter to
the Docker daemon when starting it.
For example,
Page 81
Internal Only - General
dockerd --cgroup-parent=/foobar
Default Value:
By default, docker daemon uses /docker for fs cgroup driver and system.slice for
systemd cgroup driver.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#default-cgroup-
parent
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
6 Access Control Management
Use processes and tools to create, assign, manage, and revoke access
v8 credentials and privileges for user, administrator, and service accounts for
enterprise assets and software.
v7 18 Application Software Security
Application Software Security
Page 82
Internal Only - General
2.12 Ensure base device size is not changed until needed
(Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Under certain circumstances, you might need containers larger than 10G. Where this
applies you should carefully choose the base device size.
Rationale:
The base device size can be increased on daemon restart. Increasing the base device
size allows all future images and containers to be of the new base device size. A user
can use this option to expand the base device size, however shrinking is not permitted.
This value affects the system wide “base” empty filesystem that may already be
initialized and therefore inherited by pulled images.
Although the file system does not allocate the increased size as long as it is empty,
more space will be allocated for extra images. This may cause a denial of service
condition if the allocated partition becomes full.
Impact:
None.
Audit:
To confirm this setting the dockerd start-up options and any settings in
/etc/docker/daemon.json should be reviewed.
To review the dockerd startup options, use:
grep "--storage-opt dm.basesize" /etc/docker/daemon.json
Execute the above command and it should not show any --storage-opt
dm.basesize parameters.
The contents of /etc/docker/daemon.json should also be reviewed
Remediation:
Do not set --storage-opt dm.basesize until needed.
Default Value:
The default base device size is 10G.
Page 83
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#storage-driver-
options
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.7 Use Standard Hardening Configuration Templates for
Application Infrastructure
Use standard, industry-recommended hardening configuration templates for
v8 application infrastructure components. This includes underlying servers, databases, ● ●
and web servers, and applies to cloud containers, Platform as a Service (PaaS)
components, and SaaS components. Do not allow in-house developed software to
weaken configuration hardening.
v7 18 Application Software Security
Application Software Security
Page 84
Internal Only - General
2.13 Ensure that authorization for Docker client commands is
enabled (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should use native Docker authorization plugins or a third party authorization
mechanism with the Docker daemon to manage access to Docker client commands.
Rationale:
Docker’s out-of-the-box authorization model is currently "all or nothing". This means that
any user with permission to access the Docker daemon can run any Docker client
command. The same is true for remote users accessing Docker’s API to contact the
daemon. If you require greater access control, you can create authorization plugins and
add them to your Docker daemon configuration. Using an authorization plugin, a Docker
administrator can configure granular access policies for managing access to the Docker
daemon.
Third party integrations of Docker may implement their own authorization models to
require authorization with the Docker daemon outside of docker's native authorization
plugin (i.e. Kubernetes, Cloud Foundry, Openshift).
Impact:
Each Docker command needs to pass through the authorization plugin mechanism.
This may have a performance impact.
It may be possible to use alternative mechanisms that do not have this performance hit.
Audit:
To confirm this setting the dockerd start-up options and any settings in
/etc/docker/daemon.json should be reviewed.
To review the dockerd startup options, use:
ps -ef | grep dockerd
You should ensure that the --authorization-plugin parameter is set as appropriate
if you are using docker native authorization.
The contents of /etc/docker/daemon.json should also be reviewed.
Remediation:
Step 1: Install/Create an authorization plugin.
Step 2: Configure the authorization policy as desired.
Step 3: Start the docker daemon as below:
Page 85
Internal Only - General
dockerd --authorization-plugin=<PLUGIN_ID>
Default Value:
By default, authorization plugins are not set up.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#access-
authorization
2. https://docs.docker.com/engine/extend/plugins_authorization/
Additional Information:
It should be noted that the native Docker authentication plugin is only one method of
enforcing this control so other methods which could potentially be in use should be
reviewed before assessing this as a pass or fail in an audit.
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
6 Access Control Management
Use processes and tools to create, assign, manage, and revoke access
v8 credentials and privileges for user, administrator, and service accounts for
enterprise assets and software.
v7 16 Account Monitoring and Control
Account Monitoring and Control
Page 86
Internal Only - General
2.14 Ensure centralized and remote logging is configured
(Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Docker supports various logging mechanisms. A preferable method for storing logs is
one that supports centralized and remote management.
Rationale:
Centralized and remote logging ensures that all important log records are safe even in
the event of a major data availability issue . Docker supports various logging methods
and you should use the one that best corresponds to your IT security policy.
Impact:
None.
Audit:
Run docker info and ensure that the Logging Driver property set as appropriate.
docker info --format '{{ .LoggingDriver }}'
Alternatively, the below command would give you the --log-driver setting. If
configured you should ensure that it is set appropriately.
grep "--log-driver" /etc/docker/daemon.json
The contents of /etc/docker/daemon.json should also be reviewed for this setting.
Remediation:
Step 1: Set up the desired log driver following its documentation.
Step 2: Start the docker daemon using that logging driver.
For example:
dockerd --log-driver=syslog --log-opt syslog-address=tcp://192.xxx.xxx.xxx
Default Value:
By default, container logs are maintained as json files
References:
1. https://docs.docker.com/config/containers/logging/configure/
Page 87
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
8.1 Establish and Maintain an Audit Log Management
Process
Establish and maintain an audit log management process that defines the
v8 enterprise’s logging requirements. At a minimum, address the collection, review, ● ● ●
and retention of audit logs for enterprise assets. Review and update documentation
annually, or when significant enterprise changes occur that could impact this
Safeguard.
8.9 Centralize Audit Logs
v8 Centralize, to the extent possible, audit log collection and retention across ● ●
enterprise assets.
6.6 Deploy SIEM or Log Analytic tool
v7 Deploy Security Information and Event Management (SIEM) or log analytic tool ● ●
for log correlation and analysis.
6.8 Regularly Tune SIEM
v7 On a regular basis, tune your SIEM system to better identify actionable events ●
and decrease event noise.
Page 88
Internal Only - General
2.15 Ensure containers are restricted from acquiring new
privileges (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
By default you should restrict containers from acquiring additional privileges via suid or
sgid.
Rationale:
A process can set the no_new_priv bit in the kernel and this persists across forks,
clones and execve. The no_new_priv bit ensures that the process and its child
processes do not gain any additional privileges via suid or sgid bits. This reduces the
security risks associated with many dangerous operations because there is a much
reduced ability to subvert privileged binaries.
Setting this at the daemon level ensures that by default all new containers are restricted
from acquiring new privileges.
Impact:
no_new_priv prevents LSMs such as SELinux from escalating the privileges of
individual containers.
Audit:
To confirm this setting, you should review the dockerd start-up options and a check of
any settings in /etc/docker/daemon.json should also be carried out.
To review the dockerd startup options, the following command can be used:
ps -ef | grep dockerd
You should ensure that the --no-new-privileges parameter is present and that it is
not set to false.
The contents of /etc/docker/daemon.json should also be reviewed.
Remediation:
You should run the Docker daemon as below:
dockerd --no-new-privileges
Default Value:
By default, containers are not restricted from acquiring new privileges.
Page 89
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/
2. https://github.com/moby/moby/pull/20727
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
6.1 Establish an Access Granting Process
v8 Establish and follow a process, preferably automated, for granting access to ● ● ●
enterprise assets upon new hire, rights grant, or role change of a user.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 90
Internal Only - General
2.16 Ensure live restore is enabled (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The --live-restore option enables full support of daemon-less containers within
Docker. It ensures that Docker does not stop containers on shutdown or restore and
that it properly reconnects to the container when restarted.
Rationale:
One of the important security triads is availability. Setting the --live-restore flag
within the Docker daemon ensures that container execution is not interrupted when it is
not available. This also makes it easier to update and patch the Docker daemon without
application downtime.
Impact:
None.
Audit:
You should run docker info and ensure that the Live Restore Enabled property is
set to true.
docker info --format '{{ .LiveRestoreEnabled }}'
Alternatively, you could run the below command and ensure that --live-restore is in
use.
grep "--live-restore" /etc/docker/daemon.json
The contents of /etc/docker/daemon.json should also be reviewed to ensure this
setting is in place.
Remediation:
Run Docker in daemon mode and pass --live-restore to it as an argument.
For Example,
dockerd --live-restore
Default Value:
By default, --live-restore is not enabled.
References:
1. https://docs.docker.com/config/containers/live-restore/
Page 91
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.10 Apply Secure Design Principles in Application
Architectures
Apply secure design principles in application architectures. Secure design
principles include the concept of least privilege and enforcing mediation to validate
v8 every operation that the user makes, promoting the concept of "never trust user
input." Examples include ensuring that explicit error checking is performed and
● ●
documented for all input, including for size, data type, and acceptable ranges or
formats. Secure design also means minimizing the application infrastructure attack
surface, such as turning off unprotected ports and services, removing unnecessary
programs and files, and renaming or removing default accounts.
v7 18 Application Software Security
Application Software Security
Page 92
Internal Only - General
2.17 Ensure Userland Proxy is Disabled (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The Docker daemon starts a userland proxy service for port forwarding whenever a port
is exposed. Where hairpin NAT is available, this service is generally superfluous to
requirements and can be disabled.
Rationale:
The Docker engine provides two mechanisms for forwarding ports from the host to
containers, hairpin NAT, and the use of a userland proxy. In most circumstances, the
hairpin NAT mode is preferred as it improves performance and makes use of native
Linux iptables functionality instead of using an additional component.
Where hairpin NAT is available, the userland proxy should be disabled on startup to
reduce the attack surface of the installation.
Impact:
Some systems with older Linux kernels may not be able to support hairpin NAT and
therefore require the userland proxy service. Also, some networking setups can be
impacted by the removal of the userland proxy.
Audit:
To confirm this setting, you should review the dockerd start-up options and any settings
in /etc/docker/daemon.json.
To review the dockerd startup options, use:
ps -ef | grep dockerd
Ensure that the --userland-proxy parameter is set to false.
The contents of /etc/docker/daemon.json should also be reviewed for this setting.
Remediation:
You should run the Docker daemon as below:
dockerd --userland-proxy=false
Default Value:
By default, the userland proxy is enabled.
References:
1. http://windsock.io/the-docker-proxy/
Page 93
Internal Only - General
2. https://github.com/docker/docker/issues/14856
3. https://github.com/docker/docker/issues/22741
4. https://docs.docker.com/config/containers/container-networking/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.8 Uninstall or Disable Unnecessary Services on
Enterprise Assets and Software
v8 Uninstall or disable unnecessary services on enterprise assets and software, ● ●
such as an unused file sharing service, web application module, or service
function.
9.2 Ensure Only Approved Ports, Protocols and Services
v7 Are Running ● ●
Ensure that only network ports, protocols, and services listening on a system
with validated business needs, are running on each system.
Page 94
Internal Only - General
2.18 Ensure that a daemon-wide custom seccomp profile is
applied if appropriate (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You can choose to apply a custom seccomp profile at a daemon-wide level if needed
with this overriding Docker's default seccomp profile.
Rationale:
A large number of system calls are exposed to every userland process with many of
them not utilized during the entire lifetime of the process. Many applications do not need
all these system calls and therefore benefit by having each system call currently in use
reviewed in line with organizational security policy. A reduced set of system calls
reduces the total kernel surface exposed to the application and therefore improves
application security.
A custom seccomp profile can be applied instead of Docker's default seccomp profile.
Alternatively, if Docker's default profile is adequate for your environment, you can
choose to ignore this recommendation.
Impact:
A misconfigured seccomp profile could possibly interrupt your container environment.
Docker-default blocked calls have been carefully scrutinized and address some critical
vulnerabilities/issues within container environments (for example, kernel key ring calls).
You should therefore exercise extreme care if you choose to override the default
settings.
Audit:
You should run the command below and review the seccomp profile listed in the
Security Options section. If it is default this indicates that Docker's default seccomp
profile is applied.
docker info --format '{{ .SecurityOptions }}'
Remediation:
By default, Docker's default seccomp profile is applied. If this is adequate for your
environment, no action is necessary. Alternatively, if you choose to apply your own
seccomp profile, use the --seccomp-profile flag at daemon start or put it in the
daemon runtime parameters file.
Page 95
Internal Only - General
dockerd --seccomp-profile </path/to/seccomp/profile>
Default Value:
By default, Docker applies a default seccomp profile.
References:
1. https://docs.docker.com/engine/security/seccomp/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16 Application Software Security
Manage the security life cycle of in-house developed, hosted, or acquired
v8 software to prevent, detect, and remediate security weaknesses before they can
impact the enterprise.
v7 18 Application Software Security
Application Software Security
Page 96
Internal Only - General
2.19 Ensure that experimental features are not implemented in
production (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Experimental features should not be enabled in production.
Rationale:
"Experimental" is currently a runtime Docker daemon flag rather than being a feature of
a separate build. Passing --experimental as a runtime flag to the docker daemon
activates experimental features. Whilst "Experimental" is considered a stable release, it
has a number of features which may not have been fully tested and do not guarantee
API stability.
Impact:
None
Audit:
You should run the command below and ensure that the Experimental property is set
to false in the Server section.
docker version --format '{{ .Server.Experimental }}'
Remediation:
You should not pass --experimental as a runtime parameter to the Docker daemon
on production systems.
Default Value:
By default, experimental features are not activated in the Docker daemon.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/
Page 97
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.8 Uninstall or Disable Unnecessary Services on
Enterprise Assets and Software
v8 Uninstall or disable unnecessary services on enterprise assets and software, ● ●
such as an unused file sharing service, web application module, or service
function.
v7 18 Application Software Security
Application Software Security
Page 98
Internal Only - General
3 Docker daemon configuration files
This section covers Docker related files and directory permissions and ownership.
Keeping the files and directories, that may contain sensitive parameters, secure is
important for correct and secure functioning of Docker daemon.
Page 99
Internal Only - General
3.1 Ensure that the docker.service file ownership is set to
root:root (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the docker.service file ownership and group ownership are
correctly set to root.
Rationale:
The docker.service file contains sensitive parameters that may alter the behavior of
the Docker daemon. It should therefore be individually and group owned by the root
user in order to ensure that it is not modified or corrupted by a less privileged user.
Impact:
None.
Audit:
Step 1: Find out the file location:
systemctl show -p FragmentPath docker.service
Step 2: If the file does not exist, this recommendation is not applicable. If the file exists,
execute the command below including the correct file path in order to verify that the file
is owned and group owned by root.
For example:
stat -c %U:%G /usr/lib/systemd/system/docker.service | grep -v root:root
The command above should not return anything.
Remediation:
Step 1: Find out the file location:
systemctl show -p FragmentPath docker.service
Step 2: If the file does not exist, this recommendation is not applicable. If the file does
exist, you should execute the command below, including the correct file path, in order to
set the ownership and group ownership for the file to root.
For example,
Page 100
Internal Only - General
chown root:root /usr/lib/systemd/system/docker.service
Default Value:
This file may not be present on the system and if it is not, this recommendation is not
applicable. By default, if the file is present, the correct permissions are for the ownership
and group ownership to be set to "root".
References:
1. https://docs.docker.com/config/daemon/systemd/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 101
Internal Only - General
3.2 Ensure that docker.service file permissions are appropriately
set (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the docker.service file permissions are either set to 644 or to a
more restrictive value.
Rationale:
The docker.service file contains sensitive parameters that may alter the behavior of
the Docker daemon. It should therefore not be writable by any other user other than
root in order to ensure that it can not be modified by less privileged users.
Impact:
None.
Audit:
Step 1: Find out the file location:
systemctl show -p FragmentPath docker.service
Step 2: If the file does not exist, this recommendation is not applicable. If the file exists,
execute the command below, including the correct file path in order to verify that the file
permissions are set to 644 or a more restrictive value.
For example:
stat -c %a /usr/lib/systemd/system/docker.service
Remediation:
Step 1: Find out the file location:
systemctl show -p FragmentPath docker.service
Step 2: If the file does not exist, this recommendation is not applicable. If the file exists,
execute the command below including the correct file path to set the file permissions to
644.
For example,
chmod 644 /usr/lib/systemd/system/docker.service
Default Value:
This file may not be present on the system. In that case, this recommendation is not
applicable. By default, if the file is present, the file permissions are correctly set to 644.
Page 102
Internal Only - General
References:
1. https://docs.docker.com/articles/systemd/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 103
Internal Only - General
3.3 Ensure that docker.socket file ownership is set to root:root
(Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the docker.socket file ownership and group ownership are
correctly set to root.
Rationale:
The docker.socket file contains sensitive parameters that may alter the behavior of
the Docker remote API. For this reason, it should be owned and group owned by root
in order to ensure that it is not modified by less privileged users.
Impact:
None.
Audit:
Step 1: Find out the file location:
systemctl show -p FragmentPath docker.socket
Step 2: If the file does not exist, this recommendation is not applicable. If the file exists,
execute the command below, including the correct file path to verify that the file is
owned and group-owned by root.
For example,
stat -c %U:%G /usr/lib/systemd/system/docker.socket | grep -v root:root
The command above should not return a value.
Remediation:
Step 1: Find out the file location:
systemctl show -p FragmentPath docker.socket
Step 2: If the file does not exist, this recommendation is not applicable. If the file exists,
execute the command below, including the correct file path to set the ownership and
group ownership for the file to root.
For example,
Page 104
Internal Only - General
chown root:root /usr/lib/systemd/system/docker.socket
Default Value:
This file may not be present on the system. In that case, this recommendation is not
applicable. By default, if the file is present, the ownership and group ownership for it
should be set to root.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-
socket-option
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 105
Internal Only - General
3.4 Ensure that docker.socket file permissions are set to 644 or
more restrictive (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the file permissions on the docker.socket file are correctly set to
644 or more restrictively.
Rationale:
The docker.socket file contains sensitive parameters that may alter the behavior of
the Docker remote API. It should therefore be writeable only by root in order to ensure
that it is not modified by less privileged users.
Impact:
None.
Audit:
Step 1: Find out the file location:
systemctl show -p FragmentPath docker.socket
Step 2: If the file does not exist, this recommendation is not applicable. If the file exists,
you should execute the command below, including the correct file path in order to verify
that the file permissions are set to 644 or more restrictively.
For example:
stat -c %a /usr/lib/systemd/system/docker.socket
Remediation:
Step 1: Find out the file location:
systemctl show -p FragmentPath docker.socket
Step 2: If the file does not exist, this recommendation is not applicable. If the file does
exist, you should execute the command below, including the correct file path to set the
file permissions to 644.
For example,
Page 106
Internal Only - General
chmod 644 /usr/lib/systemd/system/docker.socket
Default Value:
This file may not be present on the system and in that case, this recommendation is not
applicable. By default, if the file is present, the permissions should be set to 644 or more
restrictively.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#bind-docker-to-
another-hostport-or-a-unix-socket
2. https://github.com/YungSang/fedora-atomic-
packer/blob/master/oem/docker.socket
3. http://daviddaeschler.com/2014/12/14/centos-7rhel-7-and-docker-containers-on-
boot/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 107
Internal Only - General
3.5 Ensure that the /etc/docker directory ownership is set to
root:root (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the /etc/docker directory ownership and group ownership is
correctly set to root.
Rationale:
The /etc/docker directory contains certificates and keys in addition to various other
sensitive files. It should therefore be individual owned and group owned by root in
order to ensure that it can not be modified by less privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the directory is owned and group
owned by root:
stat -c %U:%G /etc/docker | grep -v root:root
This command should not return any data.
Remediation:
To resolve this issue you should run the following command:
chown root:root /etc/docker
This sets the ownership and group ownership for the directory to root.
Default Value:
By default, the ownership and group ownership for this directory is correctly set to root.
References:
1. https://docs.docker.com/engine/security/https/
Page 108
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 109
Internal Only - General
3.6 Ensure that /etc/docker directory permissions are set to 755 or
more restrictively (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the /etc/docker directory permissions are correctly set to 755 or
more restrictively.
Rationale:
The /etc/docker directory contains certificates and keys in addition to various
sensitive files. It should therefore only be writeable by root to ensure that it can not be
modified by a less privileged user.
Impact:
None.
Audit:
You should execute the command below to verify that the directory has permissions of
755 or more restrictive ones:
stat -c %a /etc/docker
Remediation:
You should run the following command:
chmod 755 /etc/docker
This sets the permissions for the directory to 755.
Default Value:
By default, the permissions for this directory are set to 755.
References:
1. https://docs.docker.com/engine/security/https/
Page 110
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 111
Internal Only - General
3.7 Ensure that registry certificate file ownership is set to root:root
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that all the registry certificate files (usually found under
/etc/docker/certs.d/<registry-name> directory) are individually owned and group
owned by root.
Rationale:
The /etc/docker/certs.d/<registry-name> directory contains Docker registry
certificates. These certificate files must be individually owned and group owned by root
to ensure that less privileged users are unable to modify the contents of the directory.
Impact:
None.
Audit:
You should execute the command below to verify that the registry certificate files are
individually owned and group owned by root:
stat -c %U:%G /etc/docker/certs.d/* | grep -v root:root
The above command should not return any value.
Remediation:
The following command could be executed:
chown root:root /etc/docker/certs.d/<registry-name>/*
This would set the individual ownership and group ownership for the registry certificate
files to root.
Default Value:
By default, the individual ownership and group ownership for registry certificate files is
correctly set to root.
References:
1. https://docs.docker.com/registry/insecure/
Page 112
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 113
Internal Only - General
3.8 Ensure that registry certificate file permissions are set to 444
or more restrictively (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that all the registry certificate files (usually found under
/etc/docker/certs.d/<registry-name> directory) have permissions of 444 or are
set more restrictively.
Note that, by default, this directory might not exist if no registry certificate files are in
place.
Rationale:
The /etc/docker/certs.d/<registry-name> directory contains Docker registry
certificates. These certificate files must have permissions of 444or more restrictive
permissions in order to ensure that unprivileged users do not have full access to them..
Impact:
None.
Audit:
You should execute the command below to verify that registry certificate files have
permissions of 444 or are more restrictively set.
find /etc/docker/certs.d/ -type f -exec stat -c "%a %n" {} \;
Remediation:
You should execute the following command:
find /etc/docker/certs.d/ -type f -exec chmod 0444 {} \;
This would set the permissions for the registry certificate files to 444.
Default Value:
By default, the permissions for registry certificate files might not be 444. The default file
permissions are governed by the system or user specific umask values which are
defined within the operating system itself.
References:
1. https://docs.docker.com/registry/insecure/
Page 114
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 115
Internal Only - General
3.9 Ensure that TLS CA certificate file ownership is set to root:root
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the TLS CA certificate file (the file that is passed along with the -
-tlscacert parameter) is individually owned and group owned by root.
Rationale:
The TLS CA certificate file should be protected from any tampering. It is used to
authenticate the Docker server based on a given CA certificate. It must be therefore be
individually owned and group owned by root to ensure that it cannot be modified by
less privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the TLS CA certificate file is
owned and group owned by root:
stat -c %U:%G <path to TLS CA certificate file> | grep -v root:root
The above command should return no results.
Remediation:
You should execute the following command:
chown root:root <path to TLS CA certificate file>
This sets the individual ownership and group ownership for the TLS CA certificate file to
root.
Default Value:
By default, the ownership and group-ownership for TLS CA certificate file is correctly set
to root.
References:
1. https://docs.docker.com/registry/insecure/
2. https://docs.docker.com/engine/security/https/
Page 116
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 117
Internal Only - General
3.10 Ensure that TLS CA certificate file permissions are set to 444
or more restrictively (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the TLS CA certificate file (the file that is passed along with the -
-tlscacert parameter) has permissions of 444 or is set more restrictively.
Rationale:
The TLS CA certificate file should be protected from any tampering. It is used to
authenticate the Docker server based on a given CA certificate. It must therefore have
permissions of 444, or more restrictive permissions to ensure that the file cannot be
modified by a less privileged user.
Impact:
None.
Audit:
You should execute the command below to verify that the TLS CA certificate file has
permissions of 444 or that these are more restrictively set:
stat -c %a <path to TLS CA certificate file>
Remediation:
You should execute the following command:
chmod 444 <path to TLS CA certificate file>
This sets the file permissions on the TLS CA file to 444.
Default Value:
By default, the permissions for the TLS CA certificate file might not be 444. The default
file permissions are governed by the operating system or user specific umask values.
References:
1. https://docs.docker.com/registry/insecure/
2. https://docs.docker.com/engine/security/https/
Page 118
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 119
Internal Only - General
3.11 Ensure that Docker server certificate file ownership is set to
root:root (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the Docker server certificate file (the file that is passed along with
the --tlscert parameter) is individual owned and group owned by root.
Rationale:
The Docker server certificate file should be protected from any tampering. It is used to
authenticate the Docker server based on the given server certificate. It must therefore
be individually owned and group owned by root to prevent modification by less
privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the Docker server certificate file
is individually owned and group owned by root:
stat -c %U:%G <path to Docker server certificate file> | grep -v root:root
The above command should return no results.
Remediation:
You should run the following command:
chown root:root <path to Docker server certificate file>
This sets the individual ownership and the group ownership for the Docker server
certificate file to root.
Default Value:
By default, the ownership and group-ownership for Docker server certificate file is
correctly set to root.
References:
1. https://docs.docker.com/registry/insecure/
2. https://docs.docker.com/engine/security/https/
Page 120
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 121
Internal Only - General
3.12 Ensure that the Docker server certificate file permissions are
set to 444 or more restrictively (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the Docker server certificate file (the file that is passed along with
the --tlscert parameter) has permissions of 444 or more restrictive permissions.
Rationale:
The Docker server certificate file should be protected from any tampering. It is used to
authenticate the Docker server based on the given server certificate. It should therefore
have permissions of 444 to prevent its modification.
Impact:
None.
Audit:
You should execute the command below to verify that the Docker server certificate file
has permissions of 444 or more restrictive permissions:
stat -c %a <path to Docker server certificate file>
Remediation:
You should execute the command below:
chmod 444 <path to Docker server certificate file>
This sets the file permissions of the Docker server certificate file to 444.
Default Value:
By default, the permissions for the Docker server certificate file might not be 444. The
default file permissions are governed by the operating system or user specific umask
values.
References:
1. https://docs.docker.com/registry/insecure/
2. https://docs.docker.com/engine/security/https/
Page 122
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 123
Internal Only - General
3.13 Ensure that the Docker server certificate key file ownership
is set to root:root (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the Docker server certificate key file (the file that is passed along
with the --tlskey parameter) is individually owned and group owned by root.
Rationale:
The Docker server certificate key file should be protected from any tampering or
unneeded reads/writes. As it holds the private key for the Docker server certificate, it
must be individually owned and group owned by root to ensure that it cannot be
accessed by less privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the Docker server certificate key
file is individually owned and group owned by root:
stat -c %U:%G <path to Docker server certificate key file> | grep -v
root:root
The command above should return no results.
Remediation:
You should execute the following command:
chown root:root <path to Docker server certificate key file>
This sets the individual ownership and group ownership for the Docker server certificate
key file to root.
Default Value:
By default, the individual ownership and group ownership for the Docker server
certificate key file is correctly set to root.
References:
1. https://docs.docker.com/registry/insecure/
2. https://docs.docker.com/engine/security/https/
Page 124
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 125
Internal Only - General
3.14 Ensure that the Docker server certificate key file permissions
are set to 400 (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the Docker server certificate key file (the file that is passed along
with the --tlskey parameter) has permissions of 400.
Rationale:
The Docker server certificate key file should be protected from any tampering or
unneeded reads. It holds the private key for the Docker server certificate. It must
therefore have permissions of 400 to ensure that the certificate key file is not modified.
Impact:
None.
Audit:
You should execute the command below to verify that the Docker server certificate key
file has permissions of 400:
stat -c %a <path to Docker server certificate key file>
Remediation:
You should execute the following command:
chmod 400 <path to Docker server certificate key file>
This sets the Docker server certificate key file permissions to 400.
Default Value:
By default, the permissions for the Docker server certificate key file might not be 400.
The default file permissions are governed by the operating system or user specific
umask values.
References:
1. https://docs.docker.com/registry/insecure/
2. https://docs.docker.com/engine/security/https/
Page 126
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 127
Internal Only - General
3.15 Ensure that the Docker socket file ownership is set to
root:docker (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the Docker socket file is owned by root and group owned by
docker.
Rationale:
The Docker daemon runs as root. The default Unix socket therefore must be owned by
root. If any other user or process owns this socket, it might be possible for that non-
privileged user or process to interact with the Docker daemon. Additionally, in this case
a non-privileged user or process might be able to interact with containers which is
neither a secure nor desired behavior.
Additionally, the Docker installer creates a Unix group called docker. You can add
users to this group, and in this case, those users would be able to read and write to the
default Docker Unix socket. The membership of the docker group is tightly controlled by
the system administrator. However, ff any other group owns this socket, then it might be
possible for members of that group to interact with the Docker daemon. Such a group
might not be as tightly controlled as the docker group. Again, this is not in line with
good security practice.
For these reason, the default Docker Unix socket file should be owned by root and
group owned by docker to maintain the integrity of the socket file.
Impact:
None.
Audit:
You should execute the below command to verify that the Docker socket file is owned
by root and group owned by docker:
stat -c %U:%G /var/run/docker.sock | grep -v root:docker
The command above should return no results.
Remediation:
You should execute the following command:
Page 128
Internal Only - General
chown root:docker /var/run/docker.sock
This sets the ownership to root and group ownership to docker for the default Docker
socket file.
Default Value:
By default, the ownership and group ownership for the Docker socket file is correctly set
to root:docker.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-
socket-option
2. https://docs.docker.com/engine/reference/commandline/dockerd/#bind-docker-to-
another-hostport-or-a-unix-socket
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply
v8 data access control lists, also known as access permissions, to local and remote
● ● ●
file systems, databases, and applications.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 129
Internal Only - General
3.16 Ensure that the Docker socket file permissions are set to 660
or more restrictively (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the Docker socket file has permissions of 660 or are configured
more restrictively.
Rationale:
Only root and the members of the docker group should be allowed to read and write to
the default Docker Unix socket. The Docker socket file should therefore have
permissions of 660 or more restrictive permissions.
Impact:
None.
Audit:
You should execute the command below to verify that the Docker socket file has
permissions of 660 or more restrictive permissions
stat -c %a /var/run/docker.sock
Remediation:
You should execute the command below.
chmod 660 /var/run/docker.sock
This sets the file permissions of the Docker socket file to 660.
Default Value:
By default, the permissions for the Docker socket file is correctly set to 660.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-
socket-option
2. https://docs.docker.com/engine/reference/commandline/dockerd/#bind-docker-to-
another-hostport-or-a-unix-socket
Page 130
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 131
Internal Only - General
3.17 Ensure that the daemon.json file ownership is set to root:root
(Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should verify that the daemon.json file individual ownership and group ownership
is correctly set to root, if it is in use.
Rationale:
The daemon.json file contains sensitive parameters that could alter the behavior of the
docker daemon. It should therefore be owned and group owned by root to ensure it
can not be modified by less privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the file is owned and group
owned by root:
stat -c %U:%G /etc/docker/daemon.json | grep -v root:root
The command above should not return any results or, if there is no daemon.json file
present it will return:
stat: cannot stat '/etc/docker/daemon.json': No such file or directory
Remediation:
If the daemon.json file is present, you should execute the command below:
chown root:root /etc/docker/daemon.json
This sets the ownership and group ownership for the file to root.
Default Value:
This file may not be present on the system, and in that case, this recommendation is not
applicable.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-
configuration-file
Page 132
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 133
Internal Only - General
3.18 Ensure that daemon.json file permissions are set to 644 or
more restrictive (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should verify that if the daemon.json is present its file permissions are correctly set
to 644 or more restrictively.
Rationale:
The daemon.json file contains sensitive parameters that may alter the behavior of the
docker daemon. Therefore it should be writeable only by root to ensure it is not
modified by less privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the file permissions are correctly
set to 644 or more restrictively:
stat -c %a /etc/docker/daemon.json
If the command returns the result below, the file is not present and this check does not
apply:
stat: cannot stat '/etc/docker/daemon.json': No such file or directory
Remediation:
If the file is present, you should execute the command below:
chmod 644 /etc/docker/daemon.json
This sets the file permissions for this file to 644.
Default Value:
This file may not be present on the system, and in that case, this recommendation is not
applicable.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-
configuration-file
Page 134
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 135
Internal Only - General
3.19 Ensure that the /etc/default/docker file ownership is set to
root:root (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should verify that the /etc/default/docker file ownership and group-ownership
is correctly set to root.
Rationale:
The /etc/default/docker file contains sensitive parameters that may alter the
behavior of the Docker daemon. It should therefore be individually owned and group
owned by root to ensure that it cannot be modified by less privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the file is individually owned and
group owned by root:
stat -c %U:%G /etc/default/docker | grep -v root:root
The command above should return no results.
Remediation:
You should execute the following command
chown root:root /etc/default/docker
This sets the ownership and group ownership of the file to root.
Default Value:
This file may not be present on the system, and in this case, this recommendation is not
applicable.
References:
1. https://docs.docker.com/engine/admin/configuring/
Page 136
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 137
Internal Only - General
3.20 Ensure that the /etc/default/docker file permissions are set to
644 or more restrictively (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should verify that the /etc/default/docker file permissions are correctly set to
644 or more restrictively.
Rationale:
The /etc/default/docker file contains sensitive parameters that may alter the
behavior of the Docker daemon. It should therefore be writeable only by root in order to
ensure that it is not modified by less privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the file permissions are correctly
set to 644 or more restrictively:
stat -c %a /etc/default/docker
Remediation:
You should execute the following command:
chmod 644 /etc/default/docker
This sets the file permissions for this file to 644.
Default Value:
This file may not be present on the system and in this case, this recommendation is not
applicable.
References:
1. https://docs.docker.com/engine/admin/configuring/
Page 138
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 139
Internal Only - General
3.21 Ensure that the /etc/sysconfig/docker file permissions are set
to 644 or more restrictively (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should verify that the /etc/sysconfig/docker file permissions are correctly set to
644 or more restrictively.
Rationale:
The /etc/sysconfig/docker file contains sensitive parameters that may alter the
behavior of the Docker daemon. It should therefore be writeable only by root in order to
ensure that it is not modified by less privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the file permissions are correctly
set to 644 or more restrictively:
stat -c %a /etc/sysconfig/docker
Remediation:
You should execute the following command:
chmod 644 /etc/sysconfig/docker
This sets the file permissions for this file to 644.
Default Value:
This file may not be present on the system and in this case, this recommendation is not
applicable.
References:
1. https://docs.docker.com/engine/admin/configuring/
Page 140
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 141
Internal Only - General
3.22 Ensure that the /etc/sysconfig/docker file ownership is set to
root:root (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should verify that the /etc/sysconfig/docker file individual ownership and group
ownership is correctly set to root.
Rationale:
The /etc/sysconfig/docker file contains sensitive parameters that may alter the
behavior of the Docker daemon. It should therefore be individually owned and group
owned by root to ensure that it is not modified by less privileged users.
Impact:
None.
Audit:
You should execute the command below to verify that the file is indiviually owned and
group owned by root:
stat -c %U:%G /etc/sysconfig/docker | grep -v root:root
The command above should return no results.
Remediation:
You should execute the following command:
chown root:root /etc/sysconfig/docker
This sets the ownership and group ownership for the file to root.
Default Value:
This file may not be present on the system, and in this case, this recommendation is not
applicable.
References:
1. https://docs.docker.com/engine/admin/configuring/
Page 142
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 143
Internal Only - General
3.23 Ensure that the Containerd socket file ownership is set to
root:root (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the Containerd socket file is owned by root and group owned by
root.
Rationale:
Containerd is an underlying component used by Docker to create and manage
containers. It provides a socket file similar to the Docker socket, which must be
protected from unauthorized access. If any other user or process owns this socket, it
might be possible for that non-privileged user or process to interact with the Containerd
daemon. Additionally, in this case a non-privileged user or process might be able to
interact with containers which is neither a secure nor desired behavior.
Unlike the Docker socket, there is usually no requirement for non-privileged users to
connect to the socket, so the ownership should be root:root.
Impact:
None.
Audit:
You should execute the below command to verify that the Containerd socket file is
owned by root and group owned by root:
stat -c %U:%G /run/containerd/containerd.sock | grep -v root:root
The command above should return no results.
Remediation:
You should execute the following command:
chown root:root /run/containerd/containerd.sock
This sets the ownership to root and group ownership to root for the default Containerd
socket file.
Default Value:
By default, the ownership and group ownership for the Containerd socket file is correctly
set to root:root.
Page 144
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 145
Internal Only - General
3.24 Ensure that the Containerd socket file permissions are set to
660 or more restrictively (Automated)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should verify that the Containerd socket file has permissions of 660 or are
configured more restrictively.
Rationale:
Only root and the members of the root group should be allowed to read and write to
the default Containerd Unix socket. The Containerd socket file should therefore have
permissions of 660 or more restrictive permissions.
Impact:
None.
Audit:
You should execute the command below to verify that the Docker socket file has
permissions of 660 or more restrictive permissions
stat -c %a /run/containerd/containerd.sock
Remediation:
You should execute the command below.
chmod 660 /run/containerd/containerd.sock
This sets the file permissions of the Containerd socket file to 660.
Default Value:
By default, the permissions for the Containerd socket file is correctly set to 660.
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
Page 146
Internal Only - General
Controls
Control IG 1 IG 2 IG 3
Version
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 147
Internal Only - General
4 Container Images and Build File Configuration
Container base images and build files govern the fundamentals of how a container
instance from a particular image would behave. Ensuring that you are using proper
base images and appropriate build files can be very important for building your
containerized infrastructure. Below are some of the recommendations that you should
follow for container base images and build files to ensure that your containerized
infrastructure is secure.
Page 148
Internal Only - General
4.1 Ensure that a user for the container has been created
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Containers should run as a non-root user.
Rationale:
It is good practice to run the container as a non-root user, where possible. This can be
done either via the USER directive in the Dockerfile or through gosu or similar where
used as part of the CMD or ENTRYPOINT directives.
Impact:
Running as a non-root user can present challenges where you wish to bind mount
volumes from the underlying host. In this case, care should be taken to ensure that the
user running the contained process can read and write to the bound directory, according
to their requirements.
Audit:
You should run the following command
docker ps --quiet | xargs --max-args=1 -I{} docker exec {} cat /proc/1/status
| grep '^Uid:' | awk '{print $3}'
This should return the effective UID for each container and where it returns 0, it
indicates that the container process is running as root.
Note that some services may start as the root user and then starts all other related
processes as an unprivileged user.
Remediation:
You should ensure that the Dockerfile for each container image contains the information
below:
USER <username or ID>
In this case, the user name or ID refers to the user that was found in the container base
image. If there is no specific user created in the container base image, then make use
of the useradd command to add a specific user before the USER instruction in the
Dockerfile.
For example, add the below lines in the Dockerfile to create a user in the container:
Page 149
Internal Only - General
RUN useradd -d /home/username -m -s /bin/bash username
USER username
Note: If there are users in the image that are not needed, you should consider deleting
them. After deleting those users, commit the image and then generate new instances of
the containers.
Alternatively, if it is not possible to set the USER directive in the Dockerfile, a script
running as part of the CMD or ENTRYPOINT sections of the Dockerfile should be used to
ensure that the container process switches to a non-root user.
Default Value:
By default, containers are run with root privileges and also run as the root user inside
the container.
References:
1. https://docs.docker.com/engine/reference/builder/#user
2. https://docs.docker.com/engine/reference/run/#user
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5 Account Management
Use processes and tools to assign and manage authorization to credentials for
v8 user accounts, including administrator accounts, as well as service accounts, to
enterprise assets and software.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 150
Internal Only - General
4.2 Ensure that containers use only trusted base images (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should ensure that container images you use are either written from scratch or are
based on another established and trusted base image downloaded over a secure
channel.
Rationale:
Official repositories contain Docker images curated and optimized by the Docker
community or by their vendor. There is no guarantee that these images are safe and do
not contain security vulnerabilities or malicious code. Caution should therefore be
exercised when obtaining container images from Docker and third parties and running
these images should be reviewed in line with organizational security policy.
Impact:
None.
Audit:
You should review what Docker images are present on the host by executing the
command below:
docker images
This command lists all the container images that are currently available for use on the
Docker host. You should then review the origin of each image and review its contents in
line with your organization's security policy.
You can use the command below to review the history of commits to the image.
docker history <imageName>
Remediation:
The following procedures are useful for establishing trust for a specific image.
• Configure and use Docker Content trust.
• View the history of each Docker image to evaluate its risk, dependent on the
sensitivity of the application you wish to deploy using it.
• Scan Docker images for vulnerabilities at regular intervals.
Default Value:
Not Applicable.
Page 151
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/commandline/pull/
2. https://registry.hub.docker.com/
3. https://access.redhat.com/blogs/766093/posts/1976473
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.7 Use Standard Hardening Configuration Templates for
Application Infrastructure
Use standard, industry-recommended hardening configuration templates for
v8 application infrastructure components. This includes underlying servers, databases, ● ●
and web servers, and applies to cloud containers, Platform as a Service (PaaS)
components, and SaaS components. Do not allow in-house developed software to
weaken configuration hardening.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 152
Internal Only - General
4.3 Ensure that unnecessary packages are not installed in the
container (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Containers should have as small a footprint as possible, and should not contain
unnecessary software packages which could increase their attack surface.
Rationale:
Unnecessary software should not be installed into containers, as doing so increases
their attack surface. Only packages strictly necessary for the correct operation of the
application being deployed should be installed.
Impact:
None.
Audit:
List all the running instances of containers by executing the command below:
docker ps --quiet
For each container instance, execute the relevant command for listing all installed
packages, e.g.:
docker exec $INSTANCE_ID rpm -qa
The command above lists the packages installed. You should review the list and ensure
that everything installed is actually required.
Remediation:
You should not install anything within the container that is not required.
You should consider using a minimal base image rather than the standard Centos,
Debian, or Red Hat images if you can. Some of the options available include BusyBox
and Alpine.
Not only can this trim your image size considerably, but there would also be fewer
pieces of software which could contain vectors for attack.
Default Value:
Not Applicable.
References:
1. https://docs.docker.com/develop/develop-images/baseimages/
Page 153
Internal Only - General
2. https://jpetazzo.github.io/2020/02/01/quest-minimal-docker-images-part-1/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.8 Uninstall or Disable Unnecessary Services on
Enterprise Assets and Software
v8 Uninstall or disable unnecessary services on enterprise assets and software, ● ●
such as an unused file sharing service, web application module, or service
function.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 154
Internal Only - General
4.4 Ensure images are scanned and rebuilt to include security
patches (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Images should be scanned frequently for any vulnerabilities. You should rebuild all
images to include these patches and then instantiate new containers from them.
Rationale:
Vulnerabilities are loopholes or bugs that can be exploited by hackers or malicious
users, and security patches are updates to resolve these vulnerabilities. Image
vulnerability scanning tools can be use to find vulnerabilities in images and then check
for available patches to mitigate these. Patches update the system to a more recent
code base which does not contain these problems, and being on a supported version of
the code base is very important, as vendors do not tend to supply patches for older
versions which have gone out of support. Security patches should be evaluated before
applying and patching should be implemented in line with the organization's IT Security
Policy.
Care should be taken with the results returned by vulnerability assessment tools, as
some will simply return results based on software banners, and these may not be
entirely accurate.
Impact:
None
Audit:
List all the running instances of containers by executing the command below:
docker ps --quiet
For each container instance, use the package manager within the container (assuming
there is one available) to check for the availability of security patches.
Alternatively, run image vulnerability assessment tools to scan all the images in your
environment.
Remediation:
Images should be re-built ensuring that the latest version of the base images are used,
to keep the operating system patch level at an appropriate level. Once the images have
been re-built, containers should be re-started making use of the updated images.
Page 155
Internal Only - General
Default Value:
By default, containers and images are not updated automatically to address missing
operating system security patches.
References:
1. https://docs.docker.com/engine/reference/builder/#onbuild
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
7.5 Perform Automated Vulnerability Scans of Internal
Enterprise Assets
v8 Perform automated vulnerability scans of internal enterprise assets on a ● ●
quarterly, or more frequent, basis. Conduct both authenticated and
unauthenticated scans, using a SCAP-compliant vulnerability scanning tool.
18.3 Verify That Acquired Software is Still Supported
Verify that the version of all software acquired from outside your organization is
v7 still supported by the developer or appropriately hardened based on developer
● ●
security recommendations.
Page 156
Internal Only - General
4.5 Ensure Content trust for Docker is Enabled (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Content trust is disabled by default and should be enabled in line with organizational
security policy.
Rationale:
Content trust provides the ability to use digital signatures for data sent to and received
from remote Docker registries. These signatures allow client-side verification of the
identity and the publisher of specific image tags and ensures the provenance of
container images.
Impact:
In an environment where DOCKER_CONTENT_TRUST is set, you are required to follow trust
procedures whilst working with the image related commands - build, create, pull,
push and run. You can use the --disable-content-trust flag to run individual
operations on tagged images without content trust on an as needed basis, but this
defeats the purpose of enabling content trust and therefore should be avoided wherever
possible.
Note: Content trust is currently only available for users of the public Docker Hub. It is
currently not available for the Docker Trusted Registry or for private registries.
Audit:
You should execute the following command:
echo $DOCKER_CONTENT_TRUST
This should return a value of 1.
Remediation:
To enable content trust in a bash shell, you should enter the following command:
export DOCKER_CONTENT_TRUST=1
Alternatively, you could set this environment variable in your profile file so that content
trust in enabled on every login.
Default Value:
By default, content trust is disabled.
Page 157
Internal Only - General
References:
1. https://docs.docker.com/engine/security/trust/
2. https://docs.docker.com/notary/service_architecture/
3. https://docs.docker.com/engine/reference/commandline/cli/#environment-
variables
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3 Data Protection
v8 Develop processes and technical controls to identify, classify, securely
handle, retain, and dispose of data.
v7 13 Data Protection
Data Protection
Page 158
Internal Only - General
4.6 Ensure that HEALTHCHECK instructions have been added to
container images (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should add the HEALTHCHECK instruction to your Docker container images in order
to ensure that health checks are executed against running containers.
Rationale:
An important security control is that of availability. Adding the HEALTHCHECK instruction
to your container image ensures that the Docker engine periodically checks the running
container instances against that instruction to ensure that containers are still
operational.
Based on the results of the health check, the Docker engine could terminate containers
which are not responding correctly, and instantiate new ones.
Impact:
None.
Audit:
You should run the command below to ensure that Docker images have the appropriate
HEALTHCHECK instruction configured.
docker inspect --format='{{ .Config.Healthcheck }}' <IMAGE>
Remediation:
You should follow the Docker documentation and rebuild your container images to
include the HEALTHCHECK instruction.
Default Value:
By default, HEALTHCHECK is not set.
References:
1. https://docs.docker.com/engine/reference/builder/#healthcheck
Page 159
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.12 Implement Code-Level Security Checks
v8 Apply static and dynamic analysis tools within the application life cycle to verify ●
that secure coding practices are being followed.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 160
Internal Only - General
4.7 Ensure update instructions are not used alone in Dockerfiles
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should not use OS package manager update instructions such as apt-get update
or yum update either alone or in a single line in any Dockerfiles used to generate
images under review.
Rationale:
Adding update instructions in a single line on the Dockerfile will cause the update layer
to be cached. When you then build any image later using the same instruction, this will
cause the previously cached update layer to be used, potentially preventing any fresh
updates from being applied to later builds.
Impact:
None
Audit:
Step 1: Run the command below to get the list of images:
docker images
Step 2: Run the command below against each image in the list above, looking for any
update instructions which are incorporated in a single line:
docker history <Image_ID>
Alternatively, if you have access to the Dockerfile for the image, you should verify that
there are no update instructions configured as described above.
Remediation:
You should use update instructions together with install instructions and version pinning
for packages while installing them. This will prevent caching and force the extraction of
the required versions.
Alternatively, you could use the --no-cache flag during the docker build process to
avoid using cached layers.
Default Value:
By default, Docker does not enforce any restrictions on using update instructions.
Page 161
Internal Only - General
References:
1. https://docs.docker.com/develop/develop-images/dockerfile_best-practices/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.7 Use Standard Hardening Configuration Templates for
Application Infrastructure
Use standard, industry-recommended hardening configuration templates for
v8 application infrastructure components. This includes underlying servers, databases, ● ●
and web servers, and applies to cloud containers, Platform as a Service (PaaS)
components, and SaaS components. Do not allow in-house developed software to
weaken configuration hardening.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 162
Internal Only - General
4.8 Ensure setuid and setgid permissions are removed (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
Removing setuid and setgid permissions in the images can prevent privilege escalation
attacks within containers.
Rationale:
setuid and setgid permissions can be used for privilege escalation. Whilst these
permissions can on occasion be legitimately needed, you should consider removing
them from packages which do not need them. This should be reviewed for each image.
Impact:
The above command would break all executables that depend on setuid or setgid
permissions including legitimate ones. You should therefore be careful to modify the
command to suit your requirements so that it does not reduce the permissions of
legitimate programs excessively. Because of this, you should exercise a degree of
caution and examine all processes carefully before making this type of modification in
order to avoid outages.
Audit:
You should run the command below against each image to list the executables which
have either setuid or setgid permissions:
docker export <IMAGE ID> | tar -tv 2>/dev/null | grep -E '^[-
rwx].*(s|S).*\s[0-9]'
You should then review the list and ensure that all executables configured with these
permissions actually require them.
Remediation:
You should allow setuid and setgid permissions only on executables which require
them. You could remove these permissions at build time by adding the following
command in your Dockerfile, preferably towards the end of the Dockerfile:
RUN find / -perm /6000 -type f -exec chmod a-s {} \; || true
Default Value:
Not Applicable
Page 163
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/run/#runtime-privilege-and-linux-
capabilities
2. http://man7.org/linux/man-pages/man2/setuid.2.html
3. http://man7.org/linux/man-pages/man2/setgid.2.html
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 164
Internal Only - General
4.9 Ensure that COPY is used instead of ADD in Dockerfiles
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should use the COPY instruction instead of the ADD instruction in the Dockerfile.
Rationale:
The COPY instruction simply copies files from the local host machine to the container file
system. The ADD instruction could potentially retrieve files from remote URLs and
perform operations such as unpacking them. The ADD instruction therefore introduces
security risks. For example, malicious files may be directly accessed from URLs without
scanning, or there may be vulnerabilities associated with decompressing them.
Impact:
Care needs to be taken in implementing this control if the application requires
functionality that is part of the ADD instruction, for example, if you need to retrieve files
from remote URLs.
Audit:
Run the command below to get the list of images:
docker images
Run the command below against each image in the list above and look for any ADD
instructions:
docker history <IMAGE ID>
Alternatively, if you have access to the Dockerfile for the image, you should verify that
there are no ADD instructions.
Remediation:
You should use COPY rather than ADD instructions in Dockerfiles.
Default Value:
Not Applicable
References:
1. https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#add-
or-copy
Page 165
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.7 Use Standard Hardening Configuration Templates for
Application Infrastructure
Use standard, industry-recommended hardening configuration templates for
v8 application infrastructure components. This includes underlying servers, databases, ● ●
and web servers, and applies to cloud containers, Platform as a Service (PaaS)
components, and SaaS components. Do not allow in-house developed software to
weaken configuration hardening.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 166
Internal Only - General
4.10 Ensure secrets are not stored in Dockerfiles (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Do not store any secrets in Dockerfiles.
Rationale:
Docker images are not opaque and contain information about the commands used to
build them. As such secrets should not be included in Dockerfiles used to build images
as they will be visible to any users of the image.
Impact:
A proper secrets management process will be required for Docker image building.
Audit:
Run the below command to get the list of images:
docker images
Run the below command for each image in the list above, and look for any secrets:
docker history <IMAGE ID>
Alternatively, if you have access to Dockerfile for the image, verify that there are no
secrets as described above.
Remediation:
Do not store any kind of secrets within Dockerfiles. Where secrets are required during
the build process, make use of a secrets management tool, such as the buildkit builder
included with Docker.
Default Value:
By default, there are no restrictions on storing config secrets in the Dockerfiles.
References:
1. https://docs.docker.com/develop/develop-images/build_enhancements/#new-
docker-build-secret-information
Page 167
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3 Data Protection
v8 Develop processes and technical controls to identify, classify, securely
handle, retain, and dispose of data.
v7 13 Data Protection
Data Protection
Page 168
Internal Only - General
4.11 Ensure only verified packages are installed (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should verify the authenticity of packages before installing them into images.
Rationale:
Verifying authenticity of software packages is essential for building a secure container
image. Packages with no known provenance could potentially be malicious or have
vulnerabilities that could be exploited.
Impact:
None
Audit:
Run the command below to get the list of images:
docker images
Run the command below for each image in the list above, and check how the
authenticity of the packages is being determined. This could be via the use of GPG keys
or other secure package distribution mechanisms.
docker history <IMAGE ID>
Alternatively, if you have access to Dockerfile for the image, verify that the authenticity
of the packages is checked.
Remediation:
You should use a secure package distribution mechanism of your choice to ensure the
authenticity of software packages.
Default Value:
Not Applicable
References:
1. https://www.redhat.com/sysadmin/rpm-gpg-verify-packages
2. https://help.ubuntu.com/community/SecureApt
Page 169
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
2.2 Ensure Authorized Software is Currently Supported
Ensure that only currently supported software is designated as authorized in the
software inventory for enterprise assets. If software is unsupported, yet necessary
v8 for the fulfillment of the enterprise’s mission, document an exception detailing ● ● ●
mitigating controls and residual risk acceptance. For any unsupported software
without an exception documentation, designate as unauthorized. Review the
software list to verify software support at least monthly, or more frequently.
18.3 Verify That Acquired Software is Still Supported
Verify that the version of all software acquired from outside your organization is
v7 still supported by the developer or appropriately hardened based on developer
● ●
security recommendations.
Page 170
Internal Only - General
4.12 Ensure all signed artifacts are validated (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Validate artifacts signatures before uploading to the package registry.
Rationale:
Cryptographic signature is a tool to verify artifact authenticity. Every artifact is supposed
to be signed by its creator in order to verify that it wasn't compromised until it got to the
client. Validating artifact signature before delivering it is another level of protection,
which checks that the signature hasn't been changed, which means that no one tried or
succeeded in tampering with the artifact. That sets trust between the supplier and the
client.
Audit:
Ensure every artifact in the package has been validated with its signature.
Remediation:
Validate every artifact with its signature. It is recommended to do so automatically.
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
2.7 Allowlist Authorized Scripts
Use technical controls, such as digital signatures and version control, to ensure
v8 that only authorized scripts, such as specific .ps1, .py, etc., files, are allowed to ●
execute. Block unauthorized scripts from executing. Reassess bi-annually, or more
frequently.
2.7 Utilize Application Whitelisting
Utilize application whitelisting technology on all assets to ensure that only
v7 authorized software executes and all unauthorized software is blocked from
●
executing on assets.
Page 171
Internal Only - General
5 Container Runtime Configuration
There are many security implications associated with the ways that containers are
started. Some runtime parameters can be supplied that have security consequences
that could compromise the host and the containers running on it. It is therefore very
important to verify the way in which containers are started, and which parameters are
associated with them. Container runtime configuration should be reviewed in line with
organizational security policy.
Page 172
Internal Only - General
5.1 Ensure swarm mode is not Enabled, if not needed (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Do not enable swarm mode on a Docker engine instance unless this is needed.
Rationale:
By default, a Docker engine instance will not listen on any network ports, with all
communications with the client coming over the Unix socket. When Docker swarm
mode is enabled on a Docker engine instance, multiple network ports are opened on the
system and made available to other systems on the network for the purposes of cluster
management and node communications.
Opening network ports on a system increases its attack surface and this should be
avoided unless required.
It should be noted that swarm mode is required for the operation of Docker Enterprise
components.
Impact:
Disabling swarm mode will impact the operation of Docker Enterprise components if
these are in use.
Audit:
Review the output of
docker info --format '{{ .Swarm }}'
If the output includes active true it indicates that swarm mode has been activated on
the Docker engine. In this case, you should confirm if swarm mode on the Docker
engine instance is actually needed.
Remediation:
If swarm mode has been enabled on a system in error, you should run the command
below:
docker swarm leave
Default Value:
By default, Docker swarm mode is not enabled.
Page 173
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/commandline/swarm_leave/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.8 Uninstall or Disable Unnecessary Services on
Enterprise Assets and Software
v8 Uninstall or disable unnecessary services on enterprise assets and software, ● ●
such as an unused file sharing service, web application module, or service
function.
9.2 Ensure Only Approved Ports, Protocols and Services
v7 Are Running ● ●
Ensure that only network ports, protocols, and services listening on a system
with validated business needs, are running on each system.
Page 174
Internal Only - General
5.2 Ensure that, if applicable, an AppArmor Profile is enabled
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
AppArmor is an effective and easy-to-use Linux application security system. It is
available on some Linux distributions by default, for example, on Debian and Ubuntu.
Rationale:
AppArmor protects the Linux OS and applications from various threats by enforcing a
security policy which is also known as an AppArmor profile. You can create your own
AppArmor profile for containers or use Docker's default profile. Enabling this feature
enforces security policies on containers as defined in the profile.
Impact:
The container will have the security controls defined in the AppArmor profile. It should
be noted that if the AppArmor profile is misconfigured, this may cause issues with the
operation of the container.
Audit:
You should run the command below:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
AppArmorProfile={{ .AppArmorProfile }}'
This command should return a valid AppArmor Profile for each container instance.
Remediation:
If AppArmor is applicable for your Linux OS, you should enable it.
1. Verify AppArmor is installed.
2. Create or import a AppArmor profile for Docker containers.
3. Enable enforcement of the policy.
4. Start your Docker container using the customized AppArmor profile. For
example:
docker run --interactive --tty --security-opt="apparmor:PROFILENAME" ubuntu
/bin/bash
Alternatively, Docker's default AppArmor policy can be used.
Page 175
Internal Only - General
Default Value:
By default, the docker-default AppArmor profile is applied to running containers. The
Docker binary generates this profile and then loads it into the kernel.
References:
1. https://docs.docker.com/engine/security/apparmor/
2. https://docs.docker.com/engine/reference/run/#security-configuration
3. https://docs.docker.com/engine/security/#other-kernel-security-features
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
10.5 Enable Anti-Exploitation Features
Enable anti-exploitation features on enterprise assets and software, where
v8 possible, such as Microsoft® Data Execution Prevention (DEP), Windows® ● ●
Defender Exploit Guard (WDEG), or Apple® System Integrity Protection (SIP) and
Gatekeeper™.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 176
Internal Only - General
5.3 Ensure that, if applicable, SELinux security options are set
(Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
SELinux is an effective and easy-to-use Linux application security system. It is available
by default on some distributions such as Red Hat and Fedora.
Rationale:
SELinux provides a Mandatory Access Control (MAC) system that greatly augments the
default Discretionary Access Control (DAC) model. You can therefore add an extra layer
of safety to your containers by enabling SELinux on your Linux host.
Impact:
Any restrictions defined in the SELinux policy will be applied to your containers. It
should be noted that if your SELinux policy is misconfigured, this may have an impact
on the correct operation of the affected containers.
Audit:
You should run the following command
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
SecurityOpt={{ .HostConfig.SecurityOpt }} MountLabel={{ .MountLabel }}
ProcessLabel={{ .ProcessLabel }}'
This command returns all the security options currently configured on the containers
listed. Note that even if an empty SecurityOpt is returned, the MountLabel and
ProcessLabel values will indicate if SELinux is in use.
Remediation:
If SELinux is applicable for your Linux OS, you should use it.
1. Set the SELinux State.
2. Set the SELinux Policy.
3. Create or import a SELinux policy template for Docker containers.
4. Start Docker in daemon mode with SELinux enabled. For example:
docker daemon --selinux-enabled
or by adding the following to the daemon.json configuration file:
Page 177
Internal Only - General
{
"selinux-enabled": true
}
5. Start your Docker container using the security options. For example,
docker run --interactive --tty --security-opt label=level:TopSecret centos
/bin/bash
Default Value:
By default, no SELinux security options are applied on containers.
References:
1. https://docs.docker.com/engine/security/#other-kernel-security-features
2. https://docs.docker.com/engine/reference/run/#security-configuration
3. https://access.redhat.com/documentation/en-
us/red_hat_enterprise_linux_atomic_host/7/html/container_security_guide/docker
_selinux_security_policy
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
10.5 Enable Anti-Exploitation Features
Enable anti-exploitation features on enterprise assets and software, where
v8 possible, such as Microsoft® Data Execution Prevention (DEP), Windows® ● ●
Defender Exploit Guard (WDEG), or Apple® System Integrity Protection (SIP) and
Gatekeeper™.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 178
Internal Only - General
5.4 Ensure that Linux kernel capabilities are restricted within
containers (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
By default, Docker starts containers with a restricted set of Linux kernel capabilities.
This means that any process can be granted the required capabilities instead of giving it
root access. Using Linux kernel capabilities, processes in general do not need to run as
the root user.
Rationale:
Docker supports the addition and removal of capabilities. You should remove all
capabilities not required for the correct function of the container.
Specifically, in the default capability set provided by Docker, the NET_RAW capability
should be removed if not explicitly required, as it can give an attacker with access to a
container the ability to create spoofed network traffic.
Impact:
Restrictions on processes within a container are based on which Linux capabilities are
in force.
Audit:
You should run the following command:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}: CapAdd={{
.HostConfig.CapAdd }} CapDrop={{ .HostConfig.CapDrop }}'
Verify that the added and deleted Linux kernel capabilities are in line with the ones
needed by the container process in each container instance. Specifically, ensure that
the NET_RAW capability is removed if not required.
Remediation:
You should execute the command below to add required capabilities:
docker run --cap-add={"Capability 1","Capability 2"} <Run arguments>
<Container Image Name or ID> <Command>
You should execute the command below to remove unneeded capabilities:
docker run --cap-drop={"Capability 1","Capability 2"} <Run arguments>
<Container Image Name or ID> <Command>
Alternatively, you could remove all the currently configured capabilities and then restore
only the ones you specifically use:
Page 179
Internal Only - General
docker run --cap-drop=all --cap-add={"Capability 1","Capability 2"} <Run
arguments> <Container Image Name or ID> <Command>
Note that some settings also can be configured using the --sysctl option, reducing the
need for container capabilities even further. This includes unprivileged ICMP echo
sockets without NET_RAW and allow opening any port less than 1024 without
NET_BIND_SERVICE.
Adding and removing capabilities are also possible when the docker service
command is used:
docker service create --cap-drop=all --cap-add={"Capability 1","Capability
2"} <Run arguments> <Container Image Name or ID> <Command>
Default Value:
By default, the capabilities below are applied to containers:
AUDIT_WRITE
CHOWN
DAC_OVERRIDE
FOWNER
FSETID
KILL
MKNOD
NET_BIND_SERVICE
NET_RAW
SETFCAP
SETGID
SETPCAP
SETUID
SYS_CHROOT
References:
1. https://docs.docker.com/engine/security/#linux-kernel-capabilities
2. https://docs.docker.com/compose/compose-file/compose-file-v3/#cap_add-
cap_drop
3. https://docs.docker.com/engine/reference/commandline/service_create/#options
4. https://docs.docker.com/engine/reference/commandline/run/#configure-
namespaced-kernel-parameters-sysctls-at-runtime
Page 180
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.7 Use Standard Hardening Configuration Templates for
Application Infrastructure
Use standard, industry-recommended hardening configuration templates for
v8 application infrastructure components. This includes underlying servers, databases, ● ●
and web servers, and applies to cloud containers, Platform as a Service (PaaS)
components, and SaaS components. Do not allow in-house developed software to
weaken configuration hardening.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 181
Internal Only - General
5.5 Ensure that privileged containers are not used (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Using the --privileged flag provides all Linux kernel capabilities to the container to
which it is applied and therefore overwrites the --cap-add and --cap-drop flags. For
this reason you should ensure that it is not used.
Rationale:
The --privileged flag provides all capabilities to the container to which it is applied,
and also lifts all the limitations enforced by the device cgroup controller. As a
consequence this the container has most of the rights of the underlying host. This flag
only exists to allow for specific use cases (for example running Docker within Docker)
and should not generally be used.
Impact:
If you start a container without the --privileged flag, it will not have excessive default
capabilities.
Audit:
You should run the command below:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
Privileged={{ .HostConfig.Privileged }}'
The above command should return Privileged=false for each container instance.
Remediation:
You should not run containers with the --privileged flag.
For example, do not start a container using the command below:
docker run --interactive --tty --privileged centos /bin/bash
Default Value:
False.
References:
1. https://docs.docker.com/engine/reference/run/#runtime-privilege-and-linux-
capabilities
Page 182
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 183
Internal Only - General
5.6 Ensure sensitive host system directories are not mounted on
containers (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should not allow sensitive host system directories such as those listed below to be
mounted as container volumes, especially in read-write mode.
/
/boot
/dev
/etc
/lib
/lib64
/proc
/sys
/usr
Rationale:
If sensitive directories are mounted in read-write mode, it could be possible to make
changes to files within them. This has obvious security implications and should be
avoided.
Impact:
None.
Audit:
You should run the following command:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
Volumes={{ .Mounts }}'
This command returns a list of currently mapped directories and indicates whether they
are mounted in read-write mode for each container instance.
Remediation:
You should not mount directories which are security sensitive on the host within
containers, especially in read-write mode.
Default Value:
Docker defaults to using a read-write volume but you can also mount a directory read-
only. By default, no sensitive host directories are mounted within containers.
Page 184
Internal Only - General
References:
1. https://docs.docker.com/storage/volumes/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3 Data Protection
v8 Develop processes and technical controls to identify, classify, securely
handle, retain, and dispose of data.
v7 13 Data Protection
Data Protection
Page 185
Internal Only - General
5.7 Ensure sshd is not run within containers (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The SSH daemon should not be running within the container. You should SSH into the
Docker host, and use docker exec to enter a container.
Rationale:
Running SSH within the container increases the complexity of security management by
making it
• Difficult to manage access policies and security compliance for SSH server
• Difficult to manage keys and passwords across various containers
• Difficult to manage security upgrades for SSH server
It is possible to have shell access to a container without using SSH, the needlessly
increasing the complexity of security management should be avoided.
Impact:
None.
Audit:
List all the running instances of containers by executing below command:
docker ps --quiet
For each container instance, execute the below command:
docker exec <CONTAINER ID> ps -el
Ensure that there is no process for SSH server.
Remediation:
Uninstall the SSH daemon from the container and use and use docker exec to enter a
container on the remote host.
docker exec --interactive --tty <CONTAINER ID> sh
OR
Page 186
Internal Only - General
docker attach <CONTAINER ID>
Default Value:
By default, SSH server is not running inside the container. Only one process per
container is allowed.
References:
1. https://jpetazzo.github.io/2014/06/23/docker-ssh-considered-evil/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.8 Uninstall or Disable Unnecessary Services on
Enterprise Assets and Software
v8 Uninstall or disable unnecessary services on enterprise assets and software, ● ●
such as an unused file sharing service, web application module, or service
function.
9.2 Ensure Only Approved Ports, Protocols and Services
v7 Are Running ● ●
Ensure that only network ports, protocols, and services listening on a system
with validated business needs, are running on each system.
Page 187
Internal Only - General
5.8 Ensure privileged ports are not mapped within containers
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The TCP/IP port numbers below 1024 are considered privileged ports. Normal users
and processes are not allowed to use them for various security reasons. Docker does,
however allow a container port to be mapped to a privileged port.
Rationale:
By default, if the user does not specifically declare a container port to host port
mapping, Docker automatically and correctly maps the container port to one available in
the 49153-65535 range on the host. Docker does, however, allow a container port to be
mapped to a privileged port on the host if the user explicitly declares it. This is because
containers are executed with NET_BIND_SERVICE Linux kernel capability which does not
restrict privileged port mapping. The privileged ports receive and transmit various pieces
of data which are security sensitive and allowing containers to use them is not in line
with good security practice.
Impact:
None.
Audit:
You can list all running containers instances and their port mappings by executing the
command below:
docker ps --quiet | xargs docker inspect --format '{{ .Id }}: Ports={{
.NetworkSettings.Ports }}'
You should then review the list and ensure that container ports are not mapped to host
port numbers below 1024.
Remediation:
You should not map container ports to privileged host ports when starting a container.
You should also, ensure that there is no such container to host privileged port mapping
declarations in the Dockerfile.
Default Value:
By default, mapping a container port to a privileged port on the host is allowed.
Note: There might be certain cases where you want to map privileged ports, because if
you forbid it, then the corresponding application has to run outside of a container.
Page 188
Internal Only - General
For example: HTTP and HTTPS load balancers have to bind 80/tcp and 443/tcp
respectively. Forbidding to map privileged ports effectively forbids from running those in
a container, and mandates using an external load balancer. In such cases, those
containers instances should be marked as exceptions for this recommendation.
References:
1. https://docs.docker.com/network/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
13.9 Deploy Port-Level Access Control
Deploy port-level access control. Port-level access control utilizes 802.1x, or
v8 similar network access control protocols, such as certificates, and may
●
incorporate user and/or device authentication.
9.2 Ensure Only Approved Ports, Protocols and Services
v7 Are Running ● ●
Ensure that only network ports, protocols, and services listening on a system
with validated business needs, are running on each system.
Page 189
Internal Only - General
5.9 Ensure that only needed ports are open on the container
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The dockerfile for a container image defines the ports which are opened by default on a
container instance. The list of ports are relevant to the application you are running within
the container and should only be open if they are needed.
Rationale:
A container can be run with only the ports defined in the Dockerfile for its image or can
alternatively be arbitrarily passed run time parameters to open a list of ports.
Additionally, in the course of time, the Dockerfile may undergo various changes and the
list of exposed ports may or may not still be relevant to the application you are running
within the container. Opening unneeded ports increases the attack surface of the
container and the associated containerized application. Good security practice is to only
open ports that are needed for the correct operation of the application.
Impact:
None.
Audit:
You should list all the running instances of containers and their associated port
mappings by executing the command below:
docker ps --quiet | xargs docker inspect --format '{{ .Id }}: Ports={{
.NetworkSettings.Ports }}'
You should then review the list and ensure that all the ports mapped are in fact
genuinely required by each container.
Remediation:
You should ensure that the Dockerfile for each container image only exposes needed
ports. You can also completely ignore the list of ports defined in the Dockerfile by NOT
using -P (UPPERCASE) or the --publish-all flag when starting the container.
Instead, use the -p (lowercase) or --publish flag to explicitly define the ports that you
need for a particular container instance.
For example:
Page 190
Internal Only - General
docker run --interactive --tty --publish 5000 --publish 5001 --publish 5002
centos /bin/bash
Default Value:
By default, all the ports that are listed in the Dockerfile under the EXPOSE instruction for
an image are opened when a container is run with the -P or --publish-all flags.
References:
1. https://docs.docker.com/engine/userguide/networking/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
13.9 Deploy Port-Level Access Control
Deploy port-level access control. Port-level access control utilizes 802.1x, or
v8 similar network access control protocols, such as certificates, and may
●
incorporate user and/or device authentication.
9.2 Ensure Only Approved Ports, Protocols and Services
v7 Are Running ● ●
Ensure that only network ports, protocols, and services listening on a system
with validated business needs, are running on each system.
Page 191
Internal Only - General
5.10 Ensure that the host's network namespace is not shared
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
When the networking mode on a container is set to --net=host, the container is not
placed inside a separate network stack. Effectively, applying this option instructs Docker
to not containerize the container's networking. The consequence of this is that the
container lives "outside" in the main Docker host and has full access to its network
interfaces.
Rationale:
Selecting this option is potentially dangerous. It allows the container process to open
reserved low numbered ports in the way that any other root process can. It also allows
the container to access network services such as D-bus on the Docker host. A container
process could potentially carry out undesired actions, such as shutting down the Docker
host. This option should not be used unless there is a very specific reason for enabling
it.
Impact:
None.
Audit:
You should use the command below:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
NetworkMode={{ .HostConfig.NetworkMode }}'
If this returns NetworkMode=host, it means that the --net=host option was passed
when the container was started.
Remediation:
You should not pass the --net=host option when starting any container.
Default Value:
By default, containers connect to the Docker bridge when starting and do not run in the
context of the host's network stack.
References:
1. https://docs.docker.com/network/
2. https://docs.docker.com/engine/reference/run/#network-settings
Page 192
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
12.2 Establish and Maintain a Secure Network
Architecture
v8 Establish and maintain a secure network architecture. A secure network ● ●
architecture must address segmentation, least privilege, and availability, at a
minimum.
v7 12 Boundary Defense
Boundary Defense
Page 193
Internal Only - General
5.11 Ensure that the memory usage for containers is limited
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
By default, all containers on a Docker host share resources equally. By using the
resource management capabilities of the Docker host, you can control the amount of
memory that a container is able to use.
Rationale:
By default a container can use all of the memory on the host. You can use memory limit
mechanisms to prevent a denial of service occurring where one container consumes all
of the host’s resources and other containers on the same host are therefore not able to
function. Having no limit on memory usage can lead to issues where one container can
easily make the whole system unstable and as a result unusable.
Impact:
If correct memory limits are not set on each container, one process can expand its
usage and cause other containers to run out of resources.
Audit:
You should run the command below:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}: Memory={{
.HostConfig.Memory }}'
If this command returns 0, it means that memory limits are not in place; if it returns a
non-zero value, it means that they are in place.
Remediation:
You should run the container with only as much memory as it requires by using the --
memory argument.
For example, you could run a container using the command below:
docker run -d --memory 256m centos sleep 1000
In the example above, the container is started with a memory limit of 256 MB.
Verify the memory settings by using the command below:
Page 194
Internal Only - General
docker inspect --format='{{ .Id }}: Memory={{.HostConfig.Memory}}
KernelMemory={{.HostConfig.KernelMemory}} Swap={{.HostConfig.MemorySwap}}'
<CONTAINER ID>
Default Value:
By default, all containers on a Docker host share their resources equally and no
memory limits are enforced.
References:
1. https://docs.docker.com/config/containers/resource_constraints/#limit-a-
containers-access-to-memory
2. https://docs.docker.com/config/containers/runmetrics/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.12 Segment Data Processing and Storage Based on
Sensitivity
v8 Segment data processing and storage based on the sensitivity of the data. ● ●
Do not process sensitive data on enterprise assets intended for lower sensitivity
data.
v7 18 Application Software Security
Application Software Security
Page 195
Internal Only - General
5.12 Ensure that CPU priority is set appropriately on containers
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
By default, all containers on a Docker host share resources equally. By using the
resource management capabilities of the Docker host you can control the host CPU
resources that a container may consume.
Rationale:
By default, CPU time is divided between containers equally. If you wish to control
available CPU resources amongst container instances, you can use the CPU sharing
feature. CPU sharing allows you to prioritize one container over others and prevents
lower priority containers from absorbing CPU resources which may be required by other
processes. This ensures that high priority containers are able to claim the CPU runtime
they require.
Impact:
If you do not correctly assign CPU thresholds, the container process may run out of
resources and become unresponsive. If CPU resources on the host are not
constrainted, CPU shares do not place any restrictions on individual resources.
Audit:
You should run the following command.
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
CpuShares={{ .HostConfig.CpuShares }}'
If the above command returns 0 or 1024, it means that CPU shares are not in place. If it
returns a non-zero value other than 1024, it means that they are in place.
Remediation:
You should manage the CPU runtime between your containers dependent on their
priority within your organization. To do so start the container using the --cpu-shares
argument.
For example, you could run a container as below:
Page 196
Internal Only - General
docker run -d --cpu-shares 512 centos sleep 1000
In the example above, the container is started with CPU shares of 50% of what other
containers use. So if the other container has CPU shares of 80%, this container will
have CPU shares of 40%.
Every new container will have 1024 shares of CPU by default. However, this value is
shown as 0 if you run the command mentioned in the audit section.
If you set one container’s CPU shares to 512 it will receive half of the CPU time
compared to the other containers. So if you take 1024 as 100% you can then derive the
number that you should set for respective CPU shares. For example, use 512 if you
want to set it to 50% and 256 if you want to set it 25%.
You can also view the current CPU shares in the file
/sys/fs/cgroup/cpu/docker/<CONTAINER ID>/cpu.shares.
Default Value:
By default, all containers on a Docker host share their resources equally. No CPU
shares are enforced.
References:
1. https://docs.docker.com/config/containers/resource_constraints/#cpu
2. https://docs.docker.com/engine/reference/commandline/run/#options
3. https://docs.docker.com/engine/admin/runmetrics/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.12 Segment Data Processing and Storage Based on
Sensitivity
v8 Segment data processing and storage based on the sensitivity of the data. ● ●
Do not process sensitive data on enterprise assets intended for lower sensitivity
data.
v7 18 Application Software Security
Application Software Security
Page 197
Internal Only - General
5.13 Ensure that the container's root filesystem is mounted as
read only (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The container's root filesystem should be treated as a 'golden image' by using Docker
run's --read-only option. This prevents any writes to the container's root filesystem at
container runtime and enforces the principle of immutable infrastructure.
Rationale:
Enabling this option forces containers at runtime to explicitly define their data writing
strategy to persist or not persist their data.
This also reduces security attack vectors since the container instance's filesystem
cannot be tampered with or written to unless it has explicit read-write permissions on its
filesystem folder and directories.
Impact:
Enabling --read-only at container runtime may break some container OS packages if
a data writing strategy is not defined.
You should define what the container's data should and should not persist at runtime in
order to decide which strategy to use.
Example:
• Enable use --tmpfs for temporary file writes to /tmp
• Use Docker shared data volumes for persistent data writes
Audit:
You should run the following command on the docker host:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
ReadonlyRootfs={{ .HostConfig.ReadonlyRootfs }}'
If the above command returns true, it means the container's root filesystem is mounted
read-only.
If the above command returns false, it means the container's root filesystem is
writeable.
Remediation:
You should add a --read-only flag at a container's runtime to enforce the container's
root filesystem being mounted as read only.
Page 198
Internal Only - General
docker run <Run arguments> --read-only <Container Image Name or ID> <Command>
Enabling the --read-only option at a container's runtime should be used by
administrators to force a container's executable processes to only write container data
to explicit storage locations during its lifetime.
Examples of explicit storage locations during a container's runtime include, but are not
limited to:
1. Using the --tmpfs option to mount a temporary file system for non-persistent
data writes.
docker run --interactive --tty --read-only --tmpfs "/run" --tmpfs "/tmp"
centos /bin/bash
2. Enabling Docker rw mounts at a container's runtime to persist container data
directly on the Docker host filesystem.
docker run --interactive --tty --read-only -v /opt/app/data:/run/app/data:rw
centos /bin/bash
3. Utilizing the Docker shared-storage volume plugin for Docker data volume to
persist container data.
docker volume create -d convoy --opt o=size=20GB my-named-volume
docker run --interactive --tty --read-only -v my-named-volume:/run/app/data
centos /bin/bash
3. Transmitting container data outside of the Docker controlled area during the
container's runtime for container data in order to ensure that it is persistent.
Examples include hosted databases, network file shares and APIs.
Default Value:
By default, a container has its root filesystem writeable, allowing all container processes
to write files owned by the container's actual runtime user.
References:
1. https://docs.docker.com/storage/volumes/
2. https://docs.docker.com/storage/volumes/#use-a-read-only-volume
3. https://docs.docker.com/engine/reference/commandline/run/#mount-tmpfs---
tmpfs
Page 199
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
6.8 Define and Maintain Role-Based Access Control
Define and maintain role-based access control, through determining and
documenting the access rights necessary for each role within the enterprise to
v8 successfully carry out its assigned duties. Perform access control reviews of
●
enterprise assets to validate that all privileges are authorized, on a recurring
schedule at a minimum annually, or more frequently.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share, claims,
v7 application, or database specific access control lists. These controls will enforce the ● ● ●
principle that only authorized individuals should have access to the information
based on their need to access the information as a part of their responsibilities.
Page 200
Internal Only - General
5.14 Ensure that incoming container traffic is bound to a specific
host interface (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
By default, Docker containers can make connections to the outside world, but the
outside world cannot connect to containers and each outgoing connection will appear to
originate from one of the host machine's own IP addresses. You should only allow
container services to be contacted through a specific external interface on the host
machine.
Rationale:
If you have multiple network interfaces on your host machine, the container can accept
connections on exposed ports on any network interface. This might not be desirable and
may not be secured. In many cases a specific, desired interface is exposed externally
and services such as intrusion detection, intrusion prevention, firewall, load balancing,
etc. are all run by intention there to screen incoming public traffic. You should therefore
not accept incoming connections on any random interface, but only the one designated
for this type of traffic.
Impact:
None.
Audit:
You should list all running instances of containers and their port mappings by executing
the command below:
docker ps --quiet | xargs docker inspect --format '{{ .Id }}: Ports={{
.NetworkSettings.Ports }}'
Then review the list and ensure that the exposed container ports are bound to a specific
interface and not to the wildcard IP address 0.0.0.0.
For example, if the command above returns the results below, this is non-compliant and
the container can accept connections on any host interface on the specified port 49153.
Ports=map[443/tcp:<nil> 80/tcp:[map[HostPort:49153 HostIp:0.0.0.0]]]
However, if the exposed port is bound to a specific interface on the host as below, then
this is configured in line with good security practice.
Ports=map[443/tcp:<nil> 80/tcp:[map[HostIp:10.2.3.4 HostPort:49153]]]
Remediation:
You should bind the container port to a specific host interface on the desired host port.
For example,
Page 201
Internal Only - General
docker run --detach --publish 10.2.3.4:49153:80 nginx
In the example above, the container port 80 is bound to the host port on 49153 and
would accept incoming connection only from the 10.2.3.4 external interface.
Default Value:
By default, Docker exposes the container ports on 0.0.0.0, the wildcard IP address
that will match any possible incoming network interface on the host machine.
References:
1. https://docs.docker.com/network/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.4 Implement and Manage a Firewall on Servers
Implement and manage a firewall on servers, where supported. Example
v8 implementations include a virtual firewall, operating system firewall, or a third-
● ● ●
party firewall agent.
11 Secure Configuration for Network Devices, such as
v7 Firewalls, Routers and Switches
Secure Configuration for Network Devices, such as Firewalls, Routers and
Switches
Page 202
Internal Only - General
5.15 Ensure that the 'on-failure' container restart policy is set to '5'
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
By using the --restart flag in the docker run command you can specify a restart
policy for how a container should or should not be restarted on exit. You should choose
the on-failure restart policy and limit the restart attempts to 5.
Rationale:
If you indefinitely keep trying to start the container, it could possibly lead to a denial of
service on the host. It could be an easy way to do a distributed denial of service attack
especially if you have many containers on the same host. Additionally, ignoring the exit
status of the container and always attempting to restart the container, leads to non-
investigation of the root cause behind containers getting terminated. If a container gets
terminated, you should investigate on the reason behind it instead of just attempting to
restart it indefinitely. You should use the on-failure restart policy to limit the number
of container restarts to a maximum of 5 attempts.
Impact:
If this option is set, a container will only attempt to restart itself 5 times.
Audit:
You should use the command below
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
RestartPolicyName={{ .HostConfig.RestartPolicy.Name }} MaximumRetryCount={{
.HostConfig.RestartPolicy.MaximumRetryCount }}'
If this command returns RestartPolicyName=always, then the system is not
configured optimally.
If the above command returns RestartPolicyName=no or just RestartPolicyName=,
then restart policies are not being used and the container would never be restarted
automatically. Whilst this may be a secure option, it is not the best option from a
usability standpoint.
If the above command returns RestartPolicyName=on-failure, then verify that the
number of restart attempts is set to 5 or less by looking at MaximumRetryCount.
Remediation:
If you wish a container to be automatically restarted, a sample command is as below:
Page 203
Internal Only - General
docker run --detach --restart=on-failure:5 nginx
Default Value:
By default, containers are not configured with restart policies.
References:
1. https://docs.docker.com/engine/reference/commandline/run/#restart-policies---
restart
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4 Secure Configuration of Enterprise Assets and Software
Establish and maintain the secure configuration of enterprise assets (end-user
v8 devices, including portable and mobile; network devices; non-computing/IoT
devices; and servers) and software (operating systems and applications).
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 204
Internal Only - General
5.16 Ensure that the host's process namespace is not shared
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The Process ID (PID) namespace isolates the process ID space, meaning that
processes in different PID namespaces can have the same PID. This creates process
level isolation between the containers and the host.
Rationale:
PID namespace provides separation between processes. It prevents system processes
from being visible, and allows process ids to be reused including PID 1. If the host's PID
namespace is shared with containers, it would basically allow these to see all of the
processes on the host system. This reduces the benefit of process level isolation
between the host and the containers. Under these circumstances a malicious user who
has access to a container could get access to processes on the host itself, manipulate
them, and even be able to kill them. This could allow for the host itself being shut down,
which could be extremely serious, particularly in a multi-tenanted environment. You
should not share the host's process namespace with the containers running on it.
Impact:
Container processes cannot see processes on the host system. In certain
circumstances, you may want your container to share the host's process namespace.
For example, you could build a container containing debugging tools such as strace or
gdb, and want to use these tools when debugging processes on the host. If this is
desired, then share specific host processes using the -p switch.
For example:
docker run --pid=host rhel7 strace -p 1234
Audit:
You should run the following command:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
PidMode={{ .HostConfig.PidMode }}'
If the command above returns host, it means that the host PID namespace is shared
with its containers; any other result means that the system is configured in line with
good security practice.
Page 205
Internal Only - General
Remediation:
You should not start a container with the --pid=host argument.
For example, do not start a container with the command below:
docker run --interactive --tty --pid=host centos /bin/bash
Default Value:
By default, all containers have the PID namespace enabled and the therefore the host's
process namespace is not shared with its containers.
References:
1. https://docs.docker.com/engine/reference/run/#pid-settings---pid
2. https://man7.org/linux/man-pages/man7/pid_namespaces.7.html
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.12 Segment Data Processing and Storage Based on
Sensitivity
v8 Segment data processing and storage based on the sensitivity of the data. Do ● ●
not process sensitive data on enterprise assets intended for lower sensitivity
data.
14.1 Segment the Network Based on Sensitivity
Segment the network based on the label or classification level of the
v7 information stored on the servers, locate all sensitive information on separated
● ●
Virtual Local Area Networks (VLANs).
Page 206
Internal Only - General
5.17 Ensure that the host's IPC namespace is not shared
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
IPC (POSIX/SysV IPC) namespace provides separation of named shared memory
segments, semaphores and message queues. The IPC namespace on the host should
therefore not be shared with containers and should remain isolated.
Rationale:
The IPC namespace provides separation of IPC between the host and containers. If the
host's IPC namespace is shared with the container, it would allow processes within the
container to see all of IPC communications on the host system. This would remove the
benefit of IPC level isolation between host and containers. An attacker with access to a
container could get access to the host at this level with major consequences. The IPC
namespace should therefore not be shared between the host and its containers.
Impact:
Shared memory segments are used in order to accelerate interprocess
communications, commonly in high-performance applications. If this type of application
is containerized into multiple containers, you might need to share the IPC namespace of
the containers in order to achieve high performance. Under these circumstances, you
should still only share container specific IPC namespaces and not the host IPC
namespace.
A container's IPC namespace can be shared with another container as shown below:
docker run --interactive --tty --ipc=container:e3a7a1a97c58 centos /bin/bash
Audit:
You should run the following command:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
IpcMode={{ .HostConfig.IpcMode }}'
If the command returns host, it means that the host IPC namespace is shared with the
container. Any other result means that it is not shared, and that the system is therefore
configured in line with good security practice.
Remediation:
You should not start a container with the --ipc=host argument. For example, do not
start a container as below:
Page 207
Internal Only - General
docker run --interactive --tty --ipc=host centos /bin/bash
Default Value:
By default, all containers have their IPC namespace enabled and host IPC namespace
is not shared with any container.
References:
1. https://docs.docker.com/engine/reference/run/#ipc-settings---ipc
2. https://www.man7.org/linux/man-pages/man7/ipc_namespaces.7.html
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.12 Segment Data Processing and Storage Based on
Sensitivity
v8 Segment data processing and storage based on the sensitivity of the data. Do ● ●
not process sensitive data on enterprise assets intended for lower sensitivity
data.
14.1 Segment the Network Based on Sensitivity
Segment the network based on the label or classification level of the
v7 information stored on the servers, locate all sensitive information on separated
● ●
Virtual Local Area Networks (VLANs).
Page 208
Internal Only - General
5.18 Ensure that host devices are not directly exposed to
containers (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Host devices can be directly exposed to containers at runtime. Do not directly expose
host devices to containers, especially to containers that are not trusted.
Rationale:
The --device option exposes host devices to containers and as a result of this,
containers can directly access these devices. The the container would not need to run
in privileged mode to access and manipulate them, as by default, the container is
granted this type of access. Additionally, it would possible for containers to remove
block devices from the host. You therefore should not expose host devices to containers
directly.
If for some reason you wish to expose the host device to a container you should
consider which sharing permissions you wish to use on a case by case base as
appropriate to your organization:
• r - read only
• w - writable
• m - mknod allowed
Impact:
You would not be able to use host devices directly within containers.
Audit:
You should use the command below:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
Devices={{ .HostConfig.Devices }}'
The above command would list out each device with below information:
• CgroupPermissions - For example, rwm
• PathInContainer - Device path within the container
• PathOnHost - Device path on the host
Page 209
Internal Only - General
You should verify that the host device is needed to be accessed from within the
container and that the permissions required are correctly set. If the above command
returns [], then the container does not have access to host devices and is configured in
line with good security practice.
Remediation:
You should not directly expose host devices to containers. If you do need to expose
host devices to containers, you should use granular permissions as appropriate to your
organization:
For example, do not start a container using the command below:
docker run --interactive --tty --device=/dev/tty0:/dev/tty0:rwm --
device=/dev/temp_sda:/dev/temp_sda:rwm centos bash
You should only share the host device using appropriate permissions:
docker run --interactive --tty --device=/dev/tty0:/dev/tty0:rw --
device=/dev/temp_sda:/dev/temp_sda:r centos bash
Default Value:
By default, host devices are not exposed to containers. If you do not provide sharing
permissions and choose to expose a host device to a container, the host device is be
exposed with read, write and mknod permissions.
References:
1. https://docs.docker.com/engine/reference/commandline/run/#add-host-device-to-
container---device
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 14 Controlled Access Based on the Need to Know
Controlled Access Based on the Need to Know
Page 210
Internal Only - General
5.19 Ensure that the default ulimit is overwritten at runtime if
needed (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The default ulimit is set at the Docker daemon level. However, if you need to, you may
override the default ulimit setting during container runtime.
Rationale:
ulimit provides control over the resources available to the shell and to processes
started by it. Setting system resource limits in a prudent fashion, protects against denial
of service conditions. On occasion, legitimate users and processes can accidentally
overuse system resources and cause systems be degraded or even unresponsive.
The default ulimit set at the Docker daemon level should be honored. If the default ulimit
settings are not appropriate for a particular container instance, you may override them
as an exception, but this should not be done routinely. If many of your container
instances are exceeding your ulimit settings, you should consider changing the default
settings to something that is more appropriate for your needs.
Impact:
If ulimits are not set correctly, overutilization by individual containers could make the
host system unusable.
Audit:
You should run the command below:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
Ulimits={{ .HostConfig.Ulimits }}'
This command should return Ulimits=<no value> for each container instance unless
there is a need in a specific case to override the default settings.
Remediation:
You should only override the default ulimit settings if needed in a specific case.
For example, to override default ulimit settings start a container as below:
docker run -ti -d --ulimit nofile=1024:1024 centos sleep 1000
Default Value:
Container instances inherit the default ulimit settings set at the Docker daemon level.
Page 211
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/commandline/run/#set-ulimits-in-
container---ulimit
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.12 Segment Data Processing and Storage Based on
v8 Sensitivity ● ●
Segment data processing and storage based on the sensitivity of the data. Do
not process sensitive data on enterprise assets intended for lower sensitivity data.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 212
Internal Only - General
5.20 Ensure mount propagation mode is not set to shared
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Mount propagation mode allows mounting volumes in shared, slave or private mode on
a container. Do not use shared mount propagation mode unless explicitly needed.
Rationale:
A shared mount is replicated at all mounts and changes made at any mount point are
propagated to all other mount points.
Mounting a volume in shared mode does not restrict any other container from mounting
and making changes to that volume.
As this is likely not a desirable option from a security standpoint, this feature should not
be used unless explicitly required.
Impact:
None.
Audit:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
Propagation={{range $mnt := .Mounts}} {{json $mnt.Propagation}} {{end}}'
The above command returns the propagation mode for mounted volumes. The
propagation mode should not be set to shared unless needed. The above command
might throw errors if there are no mounts. In that case, this recommendation is not
applicable.
Remediation:
Do not mount volumes in shared mode propagation.
For example, do not start a container as below:
docker run <Run arguments> --volume=/hostPath:/containerPath:shared
<Container Image Name or ID> <Command>
Default Value:
By default, the container mounts are private.
References:
1. https://docs.docker.com/storage/bind-mounts/#configure-bind-propagation
Page 213
Internal Only - General
2. https://docs.docker.com/engine/reference/run/#volume-shared-filesystems
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3 Data Protection
v8 Develop processes and technical controls to identify, classify, securely
handle, retain, and dispose of data.
v7 13 Data Protection
Data Protection
Page 214
Internal Only - General
5.21 Ensure that the host's UTS namespace is not shared
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
UTS namespaces provide isolation between two system identifiers: the hostname and
the NIS domain name. It is used to set the hostname and the domain which are visible
to running processes in that namespace. Processes running within containers do not
typically require to know either the hostname or the domain name. The UTS namespace
should therefore not be shared with the host.
Rationale:
Sharing the UTS namespace with the host provides full permission for each container to
change the hostname of the host. This is not in line with good security practice and
should not be permitted.
Impact:
None.
Audit:
You should run the following command:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
UTSMode={{ .HostConfig.UTSMode }}'
If the above command returns host, it means the host UTS namespace is shared with
the container and this recommendation is non-compliant. If the above command returns
nothing, then the host's UTS namespace is not shared. This recommendation is then
compliant.
Remediation:
You should not start a container with the --uts=host argument.
For example, do not start a container using the command below:
docker run --rm --interactive --tty --uts=host rhel7.2
Default Value:
By default, all containers have the UTS namespace enabled and the host UTS
namespace is not shared with any containers.
Page 215
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/run/#uts-settings---uts
2. https://www.man7.org/linux/man-pages/man7/uts_namespaces.7.html
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
13.4 Perform Traffic Filtering Between Network
v8 Segments ● ●
Perform traffic filtering between network segments, where appropriate.
14.1 Segment the Network Based on Sensitivity
Segment the network based on the label or classification level of the
v7 information stored on the servers, locate all sensitive information on separated
● ●
Virtual Local Area Networks (VLANs).
Page 216
Internal Only - General
5.22 Ensure the default seccomp profile is not Disabled (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
Seccomp filtering provides a means for a process to specify a filter for incoming system
calls. The default Docker seccomp profile works on a whitelist basis and allows for a
large number of common system calls, whilst blocking all others. This filtering should
not be disabled unless it causes a problem with your container application usage.
Rationale:
A large number of system calls are exposed to every userland process with many of
them going unused for the entire lifetime of the process. Most of applications do not
need all these system calls and would therefore benefit from having a reduced set of
available system calls. Having a reduced set of system calls reduces the total kernel
surface exposed to the application and thus improvises application security.
Impact:
With Docker 1.10 and greater, the default seccomp profile blocks syscalls, regardless of
--cap-add passed to the container. You should create your own custom seccomp
profile in such cases. You may also disable the default seccomp profile by passing --
security-opt=seccomp:unconfined on docker run.
Audit:
You should run the following command:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
SecurityOpt={{ .HostConfig.SecurityOpt }}'
This should return either <no value> or your modified seccomp profile. If it returns
[seccomp:unconfined], the container is running without any seccomp profiles and is
therefore not configured in line with good security practice.
Remediation:
By default, seccomp profiles are enabled. You do not need to do anything unless you
want to modify and use a modified seccomp profile.
Default Value:
When you run a container, it uses the default profile unless you override it with the --
security-opt option.
Page 217
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/run/#security-configuration
2. https://github.com/moby/moby/blob/master/profiles/seccomp/default.json
3. https://docs.docker.com/engine/security/seccomp/
4. https://www.kernel.org/doc/Documentation/prctl/seccomp_filter.txt
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.4 Implement and Manage a Firewall on Servers
Implement and manage a firewall on servers, where supported. Example
v8 implementations include a virtual firewall, operating system firewall, or a third-
● ● ●
party firewall agent.
9.5 Implement Application Firewalls
Place application firewalls in front of any critical servers to verify and validate
v7 the traffic going to the server. Any unauthorized traffic should be blocked and
●
logged.
Page 218
Internal Only - General
5.23 Ensure that docker exec commands are not used with the
privileged option (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should not use docker exec with the --privileged option.
Rationale:
Using the --privileged option in docker exec commands gives extended Linux
capabilities to the command. This could potentially be an insecure practice, particularly
when you are running containers with reduced capabilities or with enhanced restrictions.
Impact:
If you need enhanced capabilities within a container, then run it with all the permissions
it requires. These should be specified individually.
Audit:
If you have auditing enabled as recommended in Section 1, you can use the command
below to filter out docker exec commands that use the --privileged option.
ausearch -k docker | grep exec | grep privileged
Remediation:
You should not use the --privileged option in docker exec commands.
Default Value:
By default, the docker exec command runs without the --privileged option.
References:
1. https://docs.docker.com/engine/reference/commandline/exec/
2. https://docs.docker.com/engine/reference/run/#runtime-privilege-and-linux-
capabilities
Page 219
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 220
Internal Only - General
5.24 Ensure that docker exec commands are not used with the
user=root option (Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should not use docker exec with the --user=root option.
Rationale:
Using the --user=root option in a docker exec command, executes it within the
container as the root user. This could potentially be insecure, particularly when you are
running containers with reduced capabilities or enhanced restrictions.
For example, if your container is running as a tomcat user (or any other non-root user),
it would be possible to run a command through docker exec as root with the --
user=root option. This could potentially be dangerous.
Impact:
None.
Audit:
If you have auditing enabled as recommended in Section 1, you can use the command
below to filter out docker exec commands that use the --user=root option.
ausearch -k docker | grep exec | grep user
Remediation:
You should not use the --user=root option in docker exec commands.
Default Value:
By default, the docker exec command runs without the --user option.
References:
1. https://docs.docker.com/engine/reference/commandline/exec/
Page 221
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 222
Internal Only - General
5.25 Ensure that cgroup usage is confirmed (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
It is possible to attach to a particular cgroup when a container is instantiated. Confirming
cgroup usage would ensure that containers are running in defined cgroups.
Rationale:
System administrators typically define cgroups in which containers are supposed to run.
If cgroups are not explicitly defined by the system administrator, containers run in the
docker cgroup by default.
At run time, it is possible to attach a container to a different cgroup other than the one
originally defined. This usage should be monitored and confirmed, as by attaching to a
different cgroup, excess permissions and resources might be granted to the container
and this can therefore prove to be a security risk.
Impact:
None.
Audit:
You should run the following command:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
CgroupParent={{ .HostConfig.CgroupParent }}'
The above command returns the cgroup where the containers are running. If it is blank,
it means that containers are running under the default docker cgroup. Any other return
value indicates that the system is not configured in line with good security practice.
Remediation:
You should not use the --cgroup-parent option within the docker run command
unless strictly required.
Default Value:
By default, containers run under docker cgroup.
References:
1. https://docs.docker.com/engine/reference/run/#specify-custom-cgroups
Page 223
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.3 Configure Data Access Control Lists
Configure data access control lists based on a user’s need to know. Apply data
v8 access control lists, also known as access permissions, to local and remote file
● ● ●
systems, databases, and applications.
14.6 Protect Information through Access Control Lists
Protect all information stored on systems with file system, network share,
claims, application, or database specific access control lists. These controls will
v7 enforce the principle that only authorized individuals should have access to the
● ● ●
information based on their need to access the information as a part of their
responsibilities.
Page 224
Internal Only - General
5.26 Ensure that the container is restricted from acquiring
additional privileges (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should restrict the container from acquiring additional privileges via suid or sgid
bits.
Rationale:
A process can set the no_new_priv bit in the kernel and this persists across forks,
clones and execve. The no_new_priv bit ensures that the process and its child
processes do not gain any additional privileges via suid or sgid bits. This reduces the
danger associated with many operations because the possibility of subverting privileged
binaries is lessened.
Impact:
The no_new_priv option prevents LSMs like SELinux from allowing processes to
acquire new privileges
Audit:
You should run the following command:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
SecurityOpt={{ .HostConfig.SecurityOpt }}'
This command should return all the security options currently configured for containers.
no-new-privileges should be one of them.
Note that the SecurityOpt response will be empty (i.e. SecurityOpt=<no value>) even
if "no-new-privileges": true has been configured in the Docker daemon.json
configuration file.
Remediation:
You should start your container with the options below:
docker run --rm -it --security-opt=no-new-privileges ubuntu bash
Default Value:
By default, new privileges are not restricted.
References:
1. https://docs.docker.com/engine/reference/run/#security-configuration
Page 225
Internal Only - General
2. https://www.kernel.org/doc/Documentation/prctl/no_new_privs.txt
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 226
Internal Only - General
5.27 Ensure that container health is checked at runtime (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
If the container image does not have an HEALTHCHECK instruction defined, you should
use the --health-cmd parameter at container runtime to check container health.
Rationale:
If the container image you are using does not have a pre-defined HEALTHCHECK
instruction, use the --health-cmd parameter to check container health at runtime.
Based on the reported health status, remedial actions can be taken if necessary.
Impact:
None.
Audit:
You should run the command below and ensure that all containers are reporting their
health status:
docker ps --quiet | xargs docker inspect --format '{{ .Id }}: Health={{
.State.Health.Status }}'
Remediation:
You should run the container using the --health-cmd parameter.
For example:
docker run -d --health-cmd='stat /etc/passwd || exit 1' nginx
Default Value:
By default, health checks are not carried out at container runtime.
References:
1. https://docs.docker.com/engine/reference/run/#healthcheck
Page 227
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
10.5 Enable Anti-Exploitation Features
Enable anti-exploitation features on enterprise assets and software, where
v8 possible, such as Microsoft® Data Execution Prevention (DEP), Windows® ● ●
Defender Exploit Guard (WDEG), or Apple® System Integrity Protection (SIP) and
Gatekeeper™.
3.1 Run Automated Vulnerability Scanning Tools
Utilize an up-to-date SCAP-compliant vulnerability scanning tool to
v7 automatically scan all systems on the network on a weekly or more frequent basis
● ●
to identify all potential vulnerabilities on the organization's systems.
Page 228
Internal Only - General
5.28 Ensure that Docker commands always make use of the
latest version of their image (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should always ensure that you are using the latest version of the images within
your repository and not cached older versions.
Rationale:
Multiple Docker commands such as docker pull, docker run etc. are known to have
an issue where by default, they extract the local copy of the image, if present, even
though there is an updated version of the image with the same tag in the upstream
repository. This could lead to using older images containing known vulnerabilites.
Impact:
None
Audit:
You should carry out the following steps:
Step 1: Open your image repository and list the image version history for the image you
are inspecting.
Step 2: Observe the status when the docker pull command is triggered.
If the status is shown as Image is up to date, it means that you are getting the
cached version of the image.
Step 3: Match the version of the image you are running to the latest version reported in
your repository and this will tell you whether you are running the cached version or the
latest copy.
Remediation:
You should use proper version pinning mechanisms (the "latest" tag which is assigned
by default is still vulnerable to caching attacks) to avoid extracting cached older
versions. Version pinning mechanisms should be used for base images, packages, and
entire images. You can customize version pinning rules according to your requirements.
Default Value:
By default, Docker commands extract the local copy unless version pinning
mechanisms are used or the local cache is cleared.
Page 229
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/commandline/pull/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16 Application Software Security
Manage the security life cycle of in-house developed, hosted, or acquired
v8 software to prevent, detect, and remediate security weaknesses before they can
impact the enterprise.
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 230
Internal Only - General
5.29 Ensure that the PIDs cgroup limit is used (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should use the --pids-limit flag at container runtime.
Rationale:
Attackers could launch a fork bomb with a single command inside the container. This
fork bomb could crash the entire system and would require a restart of the host to make
the system functional again. Using the PIDs cgroup parameter --pids-limit would
prevent this kind of attack by restricting the number of forks that can happen inside a
container within a specified time frame.
Impact:
Set the PIDs limit value as appropriate. Incorrect values might leave containers
unusable.
Audit:
You should run the command below and ensure that PidsLimit is not set to 0 or -1. A
PidsLimit of 0 or -1 means that any number of processes can be forked concurrently
inside the container.
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
PidsLimit={{ .HostConfig.PidsLimit }}'
Remediation:
Use --pids-limit flag with an appropriate value when launching the container.
For example:
docker run -it --pids-limit 100 <Image ID>
In the above example, the number of processes allowed to run at any given time is set
to 100. After a limit of 100 concurrently running processes is reached, Docker would
restrict any new process creation.
Default Value:
The Default value for --pids-limit is 0 which means there is no restriction on the
number of forks. Note that the PIDs cgroup limit works only for kernel versions 4.3 and
higher.
Page 231
Internal Only - General
References:
1. https://docs.docker.com/engine/reference/commandline/run/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4 Secure Configuration of Enterprise Assets and Software
Establish and maintain the secure configuration of enterprise assets (end-user
v8 devices, including portable and mobile; network devices; non-computing/IoT
devices; and servers) and software (operating systems and applications).
5.2 Maintain Secure Images
Maintain secure images or templates for all systems in the enterprise based on
v7 the organization's approved configuration standards. Any new system deployment ● ●
or existing system that becomes compromised should be imaged using one of
those images or templates.
Page 232
Internal Only - General
5.30 Ensure that Docker's default bridge "docker0" is not used
(Manual)
Profile Applicability:
• Level 2 - Docker - Linux
Description:
You should not use Docker's default bridge docker0. Instead you should use Docker's
user-defined networks for container networking.
Rationale:
Docker connects virtual interfaces created in bridge mode to a common bridge called
docker0. This default networking model is vulnerable to ARP spoofing and MAC
flooding attacks as there is no filtering applied to it.
Impact:
User-defined networks need to be configured and managed in line with organizational
security policy.
Audit:
You should run the command below, and verify that containers are on a user-defined
network and not the default docker0 bridge.
docker network ls --quiet | xargs docker network inspect --format '{{ .Name
}}: {{ .Options }}'
Remediation:
You should follow the Docker documentation and set up a user-defined network. All the
containers should be run in this network.
Default Value:
By default, Docker runs containers within the default docker0 bridge.
References:
1. https://docs.docker.com/network/bridge/
Page 233
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.8 Uninstall or Disable Unnecessary Services on
Enterprise Assets and Software
v8 Uninstall or disable unnecessary services on enterprise assets and software, ● ●
such as an unused file sharing service, web application module, or service
function.
9 Limitation and Control of Network Ports, Protocols, and
v6 Services
Limitation and Control of Network Ports, Protocols, and Services
Page 234
Internal Only - General
5.31 Ensure that the host's user namespaces are not shared
(Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should not share the host's user namespaces with containers running on it.
Rationale:
User namespaces ensure that a root process inside the container will be mapped to a
non-root process outside the container. Sharing the user namespaces of the host with
the container does not therefore isolate users on the host from users in the containers.
Impact:
None
Audit:
You should run the command below and ensure that it does not return any value for
UsernsMode. If it returns a value of host, it means that the host user namespace is
shared with its containers.
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
UsernsMode={{ .HostConfig.UsernsMode }}'
Remediation:
You should not share user namespaces between host and containers.
For example, you should not run the command below:
docker run --rm -it --userns=host ubuntu bash
Default Value:
By default, the host user namespace is shared with containers unless user namespace
support is enabled.
References:
1. https://docs.docker.com/engine/security/userns-remap/
2. https://docs.docker.com/engine/reference/commandline/run/#options
Page 235
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.12 Segment Data Processing and Storage Based on
Sensitivity
v8 Segment data processing and storage based on the sensitivity of the data. Do ● ●
not process sensitive data on enterprise assets intended for lower sensitivity
data.
v7 12 Boundary Defense
Boundary Defense
14.1 Segment the Network Based on Sensitivity
Segment the network based on the label or classification level of the
v7 information stored on the servers, locate all sensitive information on separated
● ●
Virtual Local Area Networks (VLANs).
Page 236
Internal Only - General
5.32 Ensure that the Docker socket is not mounted inside any
containers (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
The Docker socket docker.sock should not be mounted inside a container.
Rationale:
If the Docker socket is mounted inside a container it could allow processes running
within the container to execute Docker commands which would effectively allow for full
control of the host.
Impact:
None
Audit:
You should run the following command:
docker ps --quiet --all | xargs docker inspect --format '{{ .Id }}:
Volumes={{ .Mounts }}' | grep docker.sock
This would return any instances where docker.sock had been mapped to a container
as a volume.
Remediation:
You should ensure that no containers mount docker.sock as a volume.
Default Value:
By default, docker.sock is not mounted inside containers.
References:
1. https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-
socket-option
Page 237
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.4 Restrict Administrator Privileges to Dedicated
Administrator Accounts
v8 Restrict administrator privileges to dedicated administrator accounts on
enterprise assets. Conduct general computing activities, such as internet
● ● ●
browsing, email, and productivity suite use, from the user’s primary, non-privileged
account.
v7 4 Controlled Use of Administrative Privileges
Controlled Use of Administrative Privileges
Page 238
Internal Only - General
6 Docker Security Operations
This section covers some of the operational security issues associated with Docker
deployments. These are best practices that should be followed where possible. Most of
the recommendations in this section simply act as reminders that organizations should
extend their current security best practices and policies to include containers.
Page 239
Internal Only - General
6.1 Ensure that image sprawl is avoided (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should not keep a large number of container images on the same host. Use only
tagged images as appropriate.
Rationale:
Tagged images are useful if you need to fall back from the "latest" version to a specific
version of an image in production. Images with unused or old tags may contain
vulnerabilities that might be exploited if instantiated.
Impact:
docker system prune -a removes all exited containers as well as all images and
volumes that are not referenced by running containers. If any images are removed, this
would result in needing to reload the images to the host.
Audit:
Step 1 Make a list of all image IDs that are currently instantiated by executing the
command below:
docker images --quiet | xargs docker inspect --format '{{ .Id }}: Image={{
.Config.Image }}'
Step 2: List all the images present on the system by executing the command below:
docker images
Step 3: Compare the list of image IDs from Step 1 and Step 2 and look for images that
are currently not in use. If any unused or old images are found, discuss with the system
administrator the need to keep such images on the system. If images are no longer
needed they should be deleted.
Remediation:
You should keep only the images that you actually need and establish a workflow to
remove old or stale images from the host. Additionally, you should use features such as
pull-by-digest to get specific images from the registry.
You can follow the steps below to find unused images on the system so they can be
deleted.
Step 1 Make a list of all image IDs that are currently instantiated by executing the
command below:
Page 240
Internal Only - General
docker images --quiet | xargs docker inspect --format '{{ .Id }}: Image={{
.Config.Image }}'
Step 2: List all the images present on the system by executing the command below:
docker images
Step 3: Compare the list of image IDs created from Step 1 and Step 2 to find out
images which are currently not being instantiated.
Step 4: Decide if you want to keep the images that are not currently in use. If they are
not needed, delete them by executing the following command:
docker rmi <IMAGE ID>
Alternatively, the docker system prune command can be used to remove dangling
images which are not tagged or, if necessary, all images that are not currently used by a
running container when used with the -a option.
Default Value:
Images and layered filesystems remain accessible on the host until the administrator
removes all tags that refer to those images or layers.
References:
1. https://docs.docker.com/config/pruning/
2. https://docs.docker.com/engine/reference/commandline/rmi/
3. https://docs.docker.com/engine/reference/commandline/pull/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
16.10 Apply Secure Design Principles in Application
Architectures
Apply secure design principles in application architectures. Secure design
principles include the concept of least privilege and enforcing mediation to validate
v8 every operation that the user makes, promoting the concept of "never trust user
input." Examples include ensuring that explicit error checking is performed and
● ●
documented for all input, including for size, data type, and acceptable ranges or
formats. Secure design also means minimizing the application infrastructure attack
surface, such as turning off unprotected ports and services, removing unnecessary
programs and files, and renaming or removing default accounts.
5.3 Securely Store Master Images
Store the master images and templates on securely configured servers,
v7 validated with integrity monitoring tools, to ensure that only authorized changes to
● ●
the images are possible.
Page 241
Internal Only - General
6.2 Ensure that container sprawl is avoided (Manual)
Profile Applicability:
• Level 1 - Docker - Linux
Description:
You should not keep a large number of containers on the same host.
Rationale:
The flexibility of containers makes it easy to run multiple instances of applications and
therefore indirectly leads to Docker images that can exist at varying security patch
levels. It also means that you are consuming host resources that otherwise could have
been used for running 'useful' containers. Having more than just an essential number of
containers on a particular host makes the system vulnerable to mishandling,
misconfiguration and fragmentation. You should therefore keep the number of
containers on a given host to the minimum number commensurate with serving
production applications.
Impact:
You should retain containers that are actively in use, and delete ones which are no
longer needed.
Audit:
Step 1 - Find the total number of containers you have on the host:
docker info --format '{{ .Containers }}'
Step 2 - Execute the commands below to find the total number of containers that are
actually running or in the stopped state on the host.
docker info --format '{{ .ContainersStopped }}'
docker info --format '{{ .ContainersRunning }}'
If the difference between the number of containers that are stopped on the host and the
number of containers that are actually running is excessive, you may be suffering from
"Container sprawl" and should review the unused containers for potential deletion.
Remediation:
You should periodically check your container inventory on each host and clean up
containers which are not in active use with the command below:
docker container prune
Default Value:
By default, Docker does not restrict the number of containers you may have on a host.
Page 242
Internal Only - General
References:
1. https://docs.docker.com/config/pruning/#prune-containers
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.12 Segment Data Processing and Storage Based on
v8 Sensitivity ● ●
Segment data processing and storage based on the sensitivity of the data. Do
not process sensitive data on enterprise assets intended for lower sensitivity data.
4 Secure Configuration of Enterprise Assets and Software
Establish and maintain the secure configuration of enterprise assets (end-user
v8 devices, including portable and mobile; network devices; non-computing/IoT
devices; and servers) and software (operating systems and applications).
5.1 Establish Secure Configurations
v7 Maintain documented, standard security configuration standards for all ● ● ●
authorized operating systems and software.
Page 243
Internal Only - General
7 Docker Swarm Configuration
This section lists the recommendations that alter and secure the behavior of the Docker
Swarm. If you are not using Docker Swarm then the recommendations in this section do
not apply.
Page 244
Internal Only - General
7.1 Ensure that the minimum number of manager nodes have
been created in a swarm (Manual)
Profile Applicability:
• Level 1 - Docker Swarm
Description:
You should ensure that the minimum number of required manager nodes is created in a
swarm.
Rationale:
Manager nodes within a swarm have control over the swarm and can change its
configuration, including modifying security parameters. Having excessive manager
nodes could render the swarm more susceptible to compromise.
If fault tolerance is not required in the manager nodes, a single node should be elected
as a manger. If fault tolerance is required then the smallest odd number to achieve the
appropriate level of tolerance should be configured. This should always be an odd
number in order to ensure that a quorum is reached.
Impact:
None
Audit:
Run docker info and verify the number of managers.
docker info --format '{{ .Swarm.Managers }}'
Alternatively run the below command.
docker node ls | grep 'Leader'
Remediation:
If an excessive number of managers is configured, the excess nodes can be demoted to
workers using the following command:
docker node demote <ID>
Where <ID> is the node ID value of the manager to be demoted.
Default Value:
Only a single manager is required to start a given cluster.
Page 245
Internal Only - General
References:
1. https://docs.docker.com/engine/swarm/manage-nodes/
2. https://docs.docker.com/engine/swarm/admin_guide/#add-manager-nodes-for-
fault-tolerance
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4 Secure Configuration of Enterprise Assets and Software
Establish and maintain the secure configuration of enterprise assets (end-user
v8 devices, including portable and mobile; network devices; non-computing/IoT
devices; and servers) and software (operating systems and applications).
5.1 Establish Secure Configurations
v7 Maintain documented, standard security configuration standards for all ● ● ●
authorized operating systems and software.
Page 246
Internal Only - General
7.2 Ensure that swarm services are bound to a specific host
interface (Manual)
Profile Applicability:
• Level 1 - Docker Swarm
Description:
By default, Docker swarm services will listen on all interfaces on the host. This may not
be necessary for the operation of the swarm where the host has multiple network
interfaces.
Rationale:
When a swarm is initialized the default value for the --listen-addr flag is
0.0.0.0:2377 which means that swarm services will listen on all interfaces on the host.
If a host has multiple network interfaces this may be undesirable as it could expose
swarm services to networks which are not involved with the operation of the swarm.
By passing a specific IP address to the --listen-addr, a specific network interface
can be specified, limiting this exposure.
Impact:
None
Audit:
You should check the network listener on port 2377 (the default for docker swarm) and
7946 (container network discovery), and confirm that it is only listening on specific
interfaces. For example, in this could be done using the following command:
ss -lp | grep -iE ':2377|:7946'
Remediation:
Resolving this issues requires re-initialization of the swarm, specifying a specific
interface for the --listen-addr parameter.
Default Value:
By default, Docker swarm services listen on all available host interfaces.
References:
1. https://docs.docker.com/engine/reference/commandline/swarm_init/#--listen-addr
2. https://docs.docker.com/engine/swarm/admin_guide/#recover-from-disaster
Page 247
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4.4 Implement and Manage a Firewall on Servers
Implement and manage a firewall on servers, where supported. Example
v8 implementations include a virtual firewall, operating system firewall, or a third-
● ● ●
party firewall agent.
9 Limitation and Control of Network Ports, Protocols, and
v7 Services
Limitation and Control of Network Ports, Protocols, and Services
Page 248
Internal Only - General
7.3 Ensure that all Docker swarm overlay networks are encrypted
(Manual)
Profile Applicability:
• Level 1 - Docker Swarm
Description:
Ensure that all Docker swarm overlay networks are encrypted.
Rationale:
By default, data exchanged between containers on nodes on the overlay network is not
encrypted. This could potentially expose traffic between containers.
Impact:
None
Audit:
You should run the command below to ensure that each overlay network has been
encrypted.
docker network ls --filter driver=overlay --quiet | xargs docker network
inspect --format '{{.Name}} {{ .Options }}'
Remediation:
You should create overlay networks the with --opt encrypted flag.
Default Value:
By default, data exchanged in overlay networks in Docker swarm mode is not
encrypted.
References:
1. https://docs.docker.com/network/overlay/#encrypt-traffic-on-an-overlay-network
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.10 Encrypt Sensitive Data in Transit
v8 Encrypt sensitive data in transit. Example implementations can include: ● ●
Transport Layer Security (TLS) and Open Secure Shell (OpenSSH).
Page 249
Internal Only - General
Controls
Control IG 1 IG 2 IG 3
Version
v7 14.4 Encrypt All Sensitive Information in Transit ● ●
Encrypt all sensitive information in transit.
Page 250
Internal Only - General
7.4 Ensure that Docker's secret management commands are
used for managing secrets in a swarm cluster (Manual)
Profile Applicability:
• Level 1 - Docker Swarm
Description:
You should use Docker's in-built secret management command for control of secrets.
Rationale:
Docker has various commands for managing secrets in a swarm cluster.
Impact:
None
Audit:
On a swarm manager node, you should run the command below and ensure docker
secret management is used in your environment where this is in line with your IT
security policy.
docker secret ls
Remediation:
You should follow the docker secret documentation and use it to manage secrets
effectively.
Default Value:
Not Applicable
References:
1. https://docs.docker.com/engine/reference/commandline/secret/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
4 Secure Configuration of Enterprise Assets and Software
Establish and maintain the secure configuration of enterprise assets (end-user
v8 devices, including portable and mobile; network devices; non-computing/IoT
devices; and servers) and software (operating systems and applications).
Page 251
Internal Only - General
Controls
Control IG 1 IG 2 IG 3
Version
5.1 Establish Secure Configurations
v7 Maintain documented, standard security configuration standards for all ● ● ●
authorized operating systems and software.
Page 252
Internal Only - General
7.5 Ensure that swarm manager is run in auto-lock mode
(Manual)
Profile Applicability:
• Level 1 - Docker Swarm
Description:
You should review whether you wish to run Docker swarm manager in auto-lock mode.
Rationale:
When Docker restarts, both the TLS key used to encrypt communication among swarm
nodes, and the key used to encrypt and decrypt Raft logs on disk, are loaded into each
manager node's memory. You could protect the mutual TLS encryption key and the key
used to encrypt and decrypt Raft logs at rest. This protection could be enabled by
initializing the swarm with the --autolock flag.
With --autolock enabled, when Docker restarts, you must unlock the swarm first,
using a key encryption key generated by Docker when the swarm was initialized.
This has benefits in a high security environment, however these should be balanced
against the support issues caused by the swarm not starting automatically if, for
example the host were to experience an outage.
Impact:
A swarm in auto-lock mode will not recover from a restart without manual intervention
from an administrator to enter the unlock key. This may not always be desirable, and
should be reviewed at a policy level.
Audit:
You should run the command below
docker info --format 'Swarm Autolock: {{
.Swarm.Cluster.Spec.EncryptionConfig.AutoLockManagers }}'
If the result is true, auto-lock mode is enable.
You could also run the command below. If a key value is returned, it means that the
swarm was initialized with the --autolock flag. If the output is no unlock key is
set, it means that swarm was NOT initialized with the --autolock flag. This should be
reviewed in line with the organization's IT Security policy.
docker swarm unlock-key
Remediation:
If you are initializing a swarm, use the command below.
Page 253
Internal Only - General
docker swarm init --autolock
If you want to set --autolock on an existing swarm manager node, use the following
command.
docker swarm update --autolock
Default Value:
By default, the swarm manager does not run in auto-lock mode.
References:
1. https://docs.docker.com/engine/swarm/swarm_manager_locking/
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
3.11 Encrypt Sensitive Data at Rest
Encrypt sensitive data at rest on servers, applications, and databases containing
sensitive data. Storage-layer encryption, also known as server-side encryption,
v8 meets the minimum requirement of this Safeguard. Additional encryption methods ● ●
may include application-layer encryption, also known as client-side encryption,
where access to the data storage device(s) does not permit access to the plain-text
data.
14.8 Encrypt Sensitive Information at Rest
Encrypt all sensitive information at rest using a tool that requires a secondary
v7 authentication mechanism not integrated into the operating system, in order to
●
access the information.
Page 254
Internal Only - General
7.6 Ensure that the swarm manager auto-lock key is rotated
periodically (Manual)
Profile Applicability:
• Level 1 - Docker Swarm
Description:
You should rotate the swarm manager auto-lock key periodically.
Rationale:
The swarm manager auto-lock key is not automatically rotated. Good security practice
is to rotate keys.
Impact:
None
Audit:
Currently, there is no mechanism to find out when the key was last rotated on a swarm
manager node. You should check with the system administrator to see if there is a key
rotation process, and how often the key is rotated.
Remediation:
You should run the command below to rotate the keys.
docker swarm unlock-key --rotate
Additionally, to facilitate auditing of this recommendation, you should maintain key
rotation records and ensure that you establish a pre-defined frequency for key rotation.
Default Value:
By default, keys are not rotated automatically.
References:
1. https://docs.docker.com/engine/reference/commandline/swarm_unlock-key/
Page 255
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.2 Use Unique Passwords
Use unique passwords for all enterprise assets. Best practice implementation
v8 includes, at a minimum, an 8-character password for accounts using MFA and a
● ● ●
14-character password for accounts not using MFA.
4.4 Use Unique Passwords
Where multi-factor authentication is not supported (such as local administrator,
v7 root, or service accounts), accounts will use passwords that are unique to that
● ●
system.
Page 256
Internal Only - General
7.7 Ensure that node certificates are rotated as appropriate
(Manual)
Profile Applicability:
• Level 1 - Docker Swarm
Description:
You should rotate swarm node certificates in line with your organizational security
policy.
Rationale:
Docker Swarm uses TLS for clustering operations between its nodes. Certificate
rotation ensures that in an event such as a compromised node or key, it is difficult to
impersonate a node. By default, node certificates are rotated every 90 days, but you
should rotate them more often or as appropriate in your environment.
Impact:
None
Audit:
Run one of the commands below and ensure that the node certificate Expiry
Duration is set as appropriate.
docker info | grep "Expiry Duration"
docker info --format 'NodeCertExpiry: {{
.Swarm.Cluster.Spec.CAConfig.NodeCertExpiry }}'
Remediation:
You should run the command to set the desired expiry time on the node certificate.
For example:
docker swarm update --cert-expiry 48h
Default Value:
By default, node certificates are rotated automatically every 90 days.
References:
1. https://docs.docker.com/engine/reference/commandline/swarm_update/#exampl
es
Page 257
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.2 Use Unique Passwords
Use unique passwords for all enterprise assets. Best practice implementation
v8 includes, at a minimum, an 8-character password for accounts using MFA and a
● ● ●
14-character password for accounts not using MFA.
4.4 Use Unique Passwords
Where multi-factor authentication is not supported (such as local administrator,
v7 root, or service accounts), accounts will use passwords that are unique to that
● ●
system.
Page 258
Internal Only - General
7.8 Ensure that CA certificates are rotated as appropriate
(Manual)
Profile Applicability:
• Level 1 - Docker Swarm
Description:
You should rotate root CA certificates as appropriate.
Rationale:
Docker Swarm uses TLS for clustering operations between its nodes. Certificate
rotation ensures that in an event such as a compromised node or key, it is difficult to
impersonate a node. Node certificates depend upon root CA certificates. For operational
security, it is important to rotate these frequently. Currently, root CA certificates are not
rotated automatically and you should therefore establish a process for rotating them in
line with your organizational security policy.
Impact:
None
Audit:
You should check the time stamp on the root CA certificate file.
For example:
ls -l /var/lib/docker/swarm/certificates/swarm-root-ca.crt
The certificate should show a time stamp in line with the organizational rotation policy.
Remediation:
You should run the command below to rotate a certificate.
docker swarm ca --rotate
Default Value:
By default, root CA certificates are not rotated.
References:
1. https://docs.docker.com/engine/swarm/how-swarm-mode-works/pki/#rotating-
the-ca-certificate
Page 259
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
5.2 Use Unique Passwords
Use unique passwords for all enterprise assets. Best practice implementation
v8 includes, at a minimum, an 8-character password for accounts using MFA and a
● ● ●
14-character password for accounts not using MFA.
4.4 Use Unique Passwords
Where multi-factor authentication is not supported (such as local administrator,
v7 root, or service accounts), accounts will use passwords that are unique to that
● ●
system.
Page 260
Internal Only - General
7.9 Ensure that management plane traffic is separated from data
plane traffic (Manual)
Profile Applicability:
• Level 1 - Docker Swarm
Description:
You should separate management plane traffic from data plane traffic.
Rationale:
Separating management plane traffic from data plane traffic ensures that these types of
traffic are segregated from each other. These traffic flows can then be individually
monitored and tied to different traffic control policies and monitoring. This also ensures
that the management plane is always reachable even if there is a great deal of traffic on
the data plane.
Impact:
This requires two network interfaces per node.
Audit:
You should run the command below on each swarm node and ensure that the
management plane address is different from the data plane address.
docker node inspect --format '{{ .Status.Addr }}' self
Remediation:
You should initialize the swarm with dedicated interfaces for management and data
planes respectively.
For example,
docker swarm init --advertise-addr=192.168.0.1 --data-path-addr=17.1.0.3
Default Value:
By default, data plane traffic is not separated from management plane traffic.
References:
1. https://docs.docker.com/engine/reference/commandline/swarm_init/#--data-path-
addr
Page 261
Internal Only - General
CIS Controls:
Controls
Control IG 1 IG 2 IG 3
Version
13.4 Perform Traffic Filtering Between Network
v8 Segments ● ●
Perform traffic filtering between network segments, where appropriate.
14.1 Segment the Network Based on Sensitivity
Segment the network based on the label or classification level of the
v7 information stored on the servers, locate all sensitive information on separated
● ●
Virtual Local Area Networks (VLANs).
Page 262
Internal Only - General
Appendix: Summary Table
CIS Benchmark Recommendation Set
Correctly
Yes No
1 Host Configuration
1.1 Linux Hosts Specific Configuration
1.1.1 Ensure a separate partition for containers has been o o
created (Manual)
1.1.2 Ensure only trusted users are allowed to control Docker o o
daemon (Manual)
1.1.3 Ensure auditing is configured for the Docker daemon o o
(Automated)
1.1.4 Ensure auditing is configured for Docker files and o o
directories - /run/containerd (Manual)
1.1.5 Ensure auditing is configured for Docker files and o o
directories - /var/lib/docker (Manual)
1.1.6 Ensure auditing is configured for Docker files and o o
directories - /etc/docker (Automated)
1.1.7 Ensure auditing is configured for Docker files and o o
directories - docker.service (Automated)
1.1.8 Ensure auditing is configured for Docker files and o o
directories - containerd.sock (Automated)
1.1.9 Ensure auditing is configured for Docker files and o o
directories - docker.sock (Automated)
1.1.10 Ensure auditing is configured for Docker files and o o
directories - /etc/default/docker (Automated)
1.1.11 Ensure auditing is configured for Docker files and o o
directories - /etc/docker/daemon.json (Automated)
Page 263
Internal Only - General
CIS Benchmark Recommendation Set
Correctly
Yes No
1.1.12 Ensure auditing is configured for Docker files and o o
directories - /etc/containerd/config.toml (Automated)
1.1.13 Ensure auditing is configured for Docker files and o o
directories - /etc/sysconfig/docker (Automated)
1.1.14 Ensure auditing is configured for Docker files and o o
directories - /usr/bin/containerd (Automated)
1.1.15 Ensure auditing is configured for Docker files and o o
directories - /usr/bin/containerd-shim (Automated)
1.1.16 Ensure auditing is configured for Docker files and o o
directories - /usr/bin/containerd-shim-runc-v1 (Manual)
1.1.17 Ensure auditing is configured for Docker files and o o
directories - /usr/bin/containerd-shim-runc-v2
(Automated)
1.1.18 Ensure auditing is configured for Docker files and o o
directories - /usr/bin/runc (Automated)
1.2 General Configuration
1.2.1 Ensure the container host has been Hardened (Manual) o o
1.2.2 Ensure that the version of Docker is up to date (Manual) o o
2 Docker daemon configuration
2.1 Run the Docker daemon as a non-root user, if possible o o
(Manual)
2.2 Ensure network traffic is restricted between containers o o
on the default bridge (Manual)
2.3 Ensure the logging level is set to 'info' (Manual) o o
2.4 Ensure Docker is allowed to make changes to iptables o o
(Manual)
2.5 Ensure insecure registries are not used (Manual) o o
Page 264
Internal Only - General
CIS Benchmark Recommendation Set
Correctly
Yes No
2.6 Ensure aufs storage driver is not used (Manual) o o
2.7 Ensure devicemapper storage driver is not used o o
(Manual)
2.8 Ensure TLS authentication for Docker daemon is o o
configured (Manual)
2.9 Ensure the default ulimit is configured appropriately o o
(Manual)
2.10 Enable user namespace support (Manual) o o
2.11 Ensure the default cgroup usage has been confirmed o o
(Manual)
2.12 Ensure base device size is not changed until needed o o
(Manual)
2.13 Ensure that authorization for Docker client commands is o o
enabled (Manual)
2.14 Ensure centralized and remote logging is configured o o
(Manual)
2.15 Ensure containers are restricted from acquiring new o o
privileges (Manual)
2.16 Ensure live restore is enabled (Manual) o o
2.17 Ensure Userland Proxy is Disabled (Manual) o o
2.18 Ensure that a daemon-wide custom seccomp profile is o o
applied if appropriate (Manual)
2.19 Ensure that experimental features are not implemented o o
in production (Manual)
3 Docker daemon configuration files
3.1 Ensure that the docker.service file ownership is set to o o
root:root (Automated)
Page 265
Internal Only - General
CIS Benchmark Recommendation Set
Correctly
Yes No
3.2 Ensure that docker.service file permissions are o o
appropriately set (Automated)
3.3 Ensure that docker.socket file ownership is set to o o
root:root (Automated)
3.4 Ensure that docker.socket file permissions are set to 644 o o
or more restrictive (Automated)
3.5 Ensure that the /etc/docker directory ownership is set to o o
root:root (Automated)
3.6 Ensure that /etc/docker directory permissions are set to o o
755 or more restrictively (Automated)
3.7 Ensure that registry certificate file ownership is set to o o
root:root (Manual)
3.8 Ensure that registry certificate file permissions are set to o o
444 or more restrictively (Manual)
3.9 Ensure that TLS CA certificate file ownership is set to o o
root:root (Manual)
3.10 Ensure that TLS CA certificate file permissions are set to o o
444 or more restrictively (Manual)
3.11 Ensure that Docker server certificate file ownership is set o o
to root:root (Manual)
3.12 Ensure that the Docker server certificate file permissions o o
are set to 444 or more restrictively (Manual)
3.13 Ensure that the Docker server certificate key file o o
ownership is set to root:root (Manual)
3.14 Ensure that the Docker server certificate key file o o
permissions are set to 400 (Manual)
3.15 Ensure that the Docker socket file ownership is set to o o
root:docker (Automated)
Page 266
Internal Only - General
CIS Benchmark Recommendation Set
Correctly
Yes No
3.16 Ensure that the Docker socket file permissions are set to o o
660 or more restrictively (Automated)
3.17 Ensure that the daemon.json file ownership is set to o o
root:root (Manual)
3.18 Ensure that daemon.json file permissions are set to 644 o o
or more restrictive (Manual)
3.19 Ensure that the /etc/default/docker file ownership is set o o
to root:root (Manual)
3.20 Ensure that the /etc/default/docker file permissions are o o
set to 644 or more restrictively (Manual)
3.21 Ensure that the /etc/sysconfig/docker file permissions o o
are set to 644 or more restrictively (Manual)
3.22 Ensure that the /etc/sysconfig/docker file ownership is o o
set to root:root (Manual)
3.23 Ensure that the Containerd socket file ownership is set to o o
root:root (Automated)
3.24 Ensure that the Containerd socket file permissions are o o
set to 660 or more restrictively (Automated)
4 Container Images and Build File Configuration
4.1 Ensure that a user for the container has been created o o
(Manual)
4.2 Ensure that containers use only trusted base images o o
(Manual)
4.3 Ensure that unnecessary packages are not installed in o o
the container (Manual)
4.4 Ensure images are scanned and rebuilt to include o o
security patches (Manual)
4.5 Ensure Content trust for Docker is Enabled (Manual) o o
Page 267
Internal Only - General
CIS Benchmark Recommendation Set
Correctly
Yes No
4.6 Ensure that HEALTHCHECK instructions have been o o
added to container images (Manual)
4.7 Ensure update instructions are not used alone in o o
Dockerfiles (Manual)
4.8 Ensure setuid and setgid permissions are removed o o
(Manual)
4.9 Ensure that COPY is used instead of ADD in Dockerfiles o o
(Manual)
4.10 Ensure secrets are not stored in Dockerfiles (Manual) o o
4.11 Ensure only verified packages are installed (Manual) o o
4.12 Ensure all signed artifacts are validated (Manual) o o
5 Container Runtime Configuration
5.1 Ensure swarm mode is not Enabled, if not needed o o
(Manual)
5.2 Ensure that, if applicable, an AppArmor Profile is o o
enabled (Manual)
5.3 Ensure that, if applicable, SELinux security options are o o
set (Manual)
5.4 Ensure that Linux kernel capabilities are restricted within o o
containers (Manual)
5.5 Ensure that privileged containers are not used (Manual) o o
5.6 Ensure sensitive host system directories are not o o
mounted on containers (Manual)
5.7 Ensure sshd is not run within containers (Manual) o o
5.8 Ensure privileged ports are not mapped within containers o o
(Manual)
Page 268
Internal Only - General
CIS Benchmark Recommendation Set
Correctly
Yes No
5.9 Ensure that only needed ports are open on the container o o
(Manual)
5.10 Ensure that the host's network namespace is not shared o o
(Manual)
5.11 Ensure that the memory usage for containers is limited o o
(Manual)
5.12 Ensure that CPU priority is set appropriately on o o
containers (Manual)
5.13 Ensure that the container's root filesystem is mounted as o o
read only (Manual)
5.14 Ensure that incoming container traffic is bound to a o o
specific host interface (Manual)
5.15 Ensure that the 'on-failure' container restart policy is set o o
to '5' (Manual)
5.16 Ensure that the host's process namespace is not shared o o
(Manual)
5.17 Ensure that the host's IPC namespace is not shared o o
(Manual)
5.18 Ensure that host devices are not directly exposed to o o
containers (Manual)
5.19 Ensure that the default ulimit is overwritten at runtime if o o
needed (Manual)
5.20 Ensure mount propagation mode is not set to shared o o
(Manual)
5.21 Ensure that the host's UTS namespace is not shared o o
(Manual)
5.22 Ensure the default seccomp profile is not Disabled o o
(Manual)
Page 269
Internal Only - General
CIS Benchmark Recommendation Set
Correctly
Yes No
5.23 Ensure that docker exec commands are not used with o o
the privileged option (Manual)
5.24 Ensure that docker exec commands are not used with o o
the user=root option (Manual)
5.25 Ensure that cgroup usage is confirmed (Manual) o o
5.26 Ensure that the container is restricted from acquiring o o
additional privileges (Manual)
5.27 Ensure that container health is checked at runtime o o
(Manual)
5.28 Ensure that Docker commands always make use of the o o
latest version of their image (Manual)
5.29 Ensure that the PIDs cgroup limit is used (Manual) o o
5.30 Ensure that Docker's default bridge "docker0" is not used o o
(Manual)
5.31 Ensure that the host's user namespaces are not shared o o
(Manual)
5.32 Ensure that the Docker socket is not mounted inside any o o
containers (Manual)
6 Docker Security Operations
6.1 Ensure that image sprawl is avoided (Manual) o o
6.2 Ensure that container sprawl is avoided (Manual) o o
7 Docker Swarm Configuration
7.1 Ensure that the minimum number of manager nodes o o
have been created in a swarm (Manual)
7.2 Ensure that swarm services are bound to a specific host o o
interface (Manual)
Page 270
Internal Only - General
CIS Benchmark Recommendation Set
Correctly
Yes No
7.3 Ensure that all Docker swarm overlay networks are o o
encrypted (Manual)
7.4 Ensure that Docker's secret management commands o o
are used for managing secrets in a swarm cluster
(Manual)
7.5 Ensure that swarm manager is run in auto-lock mode o o
(Manual)
7.6 Ensure that the swarm manager auto-lock key is rotated o o
periodically (Manual)
7.7 Ensure that node certificates are rotated as appropriate o o
(Manual)
7.8 Ensure that CA certificates are rotated as appropriate o o
(Manual)
7.9 Ensure that management plane traffic is separated from o o
data plane traffic (Manual)
Page 271
Internal Only - General
Appendix: CIS Controls v7 IG 1 Mapped
Recommendations
Recommendation Set
Correctly
Yes No
1.1.3 Ensure auditing is configured for the Docker daemon o o
2.3 Ensure the logging level is set to 'info' o o
3.2 Ensure that docker.service file permissions are
o o
appropriately set
3.4 Ensure that docker.socket file permissions are set to 644
o o
or more restrictive
3.6 Ensure that /etc/docker directory permissions are set to
o o
755 or more restrictively
3.8 Ensure that registry certificate file permissions are set to
o o
444 or more restrictively
3.10 Ensure that TLS CA certificate file permissions are set to
o o
444 or more restrictively
3.12 Ensure that the Docker server certificate file permissions
o o
are set to 444 or more restrictively
3.14 Ensure that the Docker server certificate key file
o o
permissions are set to 400
3.16 Ensure that the Docker socket file permissions are set to
o o
660 or more restrictively
3.18 Ensure that daemon.json file permissions are set to 644
o o
or more restrictive
3.20 Ensure that the /etc/default/docker file permissions are
o o
set to 644 or more restrictively
3.21 Ensure that the /etc/sysconfig/docker file permissions are
o o
set to 644 or more restrictively
3.24 Ensure that the Containerd socket file permissions are
o o
set to 660 or more restrictively
5.13 Ensure that the container's root filesystem is mounted as
o o
read only
5.25 Ensure that cgroup usage is confirmed o o
6.2 Ensure that container sprawl is avoided o o
Page 272
Internal Only - General
Recommendation Set
Correctly
Yes No
7.1 Ensure that the minimum number of manager nodes
o o
have been created in a swarm
7.4 Ensure that Docker's secret management commands are
o o
used for managing secrets in a swarm cluster
Page 273
Internal Only - General
Appendix: CIS Controls v7 IG 2 Mapped
Recommendations
Recommendation Set
Correctly
Yes No
1.1.3 Ensure auditing is configured for the Docker daemon o o
2.3 Ensure the logging level is set to 'info' o o
2.5 Ensure insecure registries are not used o o
2.8 Ensure TLS authentication for Docker daemon is
o o
configured
2.14 Ensure centralized and remote logging is configured o o
2.17 Ensure Userland Proxy is Disabled o o
3.2 Ensure that docker.service file permissions are
o o
appropriately set
3.4 Ensure that docker.socket file permissions are set to 644
o o
or more restrictive
3.6 Ensure that /etc/docker directory permissions are set to
o o
755 or more restrictively
3.8 Ensure that registry certificate file permissions are set to
o o
444 or more restrictively
3.10 Ensure that TLS CA certificate file permissions are set to
o o
444 or more restrictively
3.12 Ensure that the Docker server certificate file permissions
o o
are set to 444 or more restrictively
3.14 Ensure that the Docker server certificate key file
o o
permissions are set to 400
3.16 Ensure that the Docker socket file permissions are set to
o o
660 or more restrictively
3.18 Ensure that daemon.json file permissions are set to 644
o o
or more restrictive
3.20 Ensure that the /etc/default/docker file permissions are
o o
set to 644 or more restrictively
3.21 Ensure that the /etc/sysconfig/docker file permissions are
o o
set to 644 or more restrictively
Page 274
Internal Only - General
Recommendation Set
Correctly
Yes No
3.24 Ensure that the Containerd socket file permissions are
o o
set to 660 or more restrictively
4.2 Ensure that containers use only trusted base images o o
4.3 Ensure that unnecessary packages are not installed in
o o
the container
4.4 Ensure images are scanned and rebuilt to include
o o
security patches
4.6 Ensure that HEALTHCHECK instructions have been
o o
added to container images
4.7 Ensure update instructions are not used alone in
o o
Dockerfiles
4.9 Ensure that COPY is used instead of ADD in Dockerfiles o o
4.11 Ensure only verified packages are installed o o
5.1 Ensure swarm mode is not Enabled, if not needed o o
5.2 Ensure that, if applicable, an AppArmor Profile is enabled o o
5.3 Ensure that, if applicable, SELinux security options are
o o
set
5.4 Ensure that Linux kernel capabilities are restricted within
o o
containers
5.7 Ensure sshd is not run within containers o o
5.8 Ensure privileged ports are not mapped within containers o o
5.9 Ensure that only needed ports are open on the container o o
5.13 Ensure that the container's root filesystem is mounted as
o o
read only
5.15 Ensure that the 'on-failure' container restart policy is set
o o
to '5'
5.16 Ensure that the host's process namespace is not shared o o
5.17 Ensure that the host's IPC namespace is not shared o o
5.19 Ensure that the default ulimit is overwritten at runtime if
o o
needed
5.21 Ensure that the host's UTS namespace is not shared o o
5.25 Ensure that cgroup usage is confirmed o o
5.27 Ensure that container health is checked at runtime o o
Page 275
Internal Only - General
Recommendation Set
Correctly
Yes No
5.28 Ensure that Docker commands always make use of the
o o
latest version of their image
5.29 Ensure that the PIDs cgroup limit is used o o
5.31 Ensure that the host's user namespaces are not shared o o
6.1 Ensure that image sprawl is avoided o o
6.2 Ensure that container sprawl is avoided o o
7.1 Ensure that the minimum number of manager nodes
o o
have been created in a swarm
7.3 Ensure that all Docker swarm overlay networks are
o o
encrypted
7.4 Ensure that Docker's secret management commands are
o o
used for managing secrets in a swarm cluster
7.6 Ensure that the swarm manager auto-lock key is rotated
o o
periodically
7.7 Ensure that node certificates are rotated as appropriate o o
7.8 Ensure that CA certificates are rotated as appropriate o o
7.9 Ensure that management plane traffic is separated from
o o
data plane traffic
Page 276
Internal Only - General
Appendix: CIS Controls v7 IG 3 Mapped
Recommendations
Recommendation Set
Correctly
Yes No
1.1.3 Ensure auditing is configured for the Docker daemon o o
1.1.4 Ensure auditing is configured for Docker files and
o o
directories - /run/containerd
1.1.5 Ensure auditing is configured for Docker files and
o o
directories - /var/lib/docker
1.1.6 Ensure auditing is configured for Docker files and
o o
directories - /etc/docker
1.1.7 Ensure auditing is configured for Docker files and
o o
directories - docker.service
1.1.8 Ensure auditing is configured for Docker files and
o o
directories - containerd.sock
1.1.9 Ensure auditing is configured for Docker files and
o o
directories - docker.sock
1.1.10 Ensure auditing is configured for Docker files and
o o
directories - /etc/default/docker
1.1.11 Ensure auditing is configured for Docker files and
o o
directories - /etc/docker/daemon.json
1.1.12 Ensure auditing is configured for Docker files and
o o
directories - /etc/containerd/config.toml
1.1.13 Ensure auditing is configured for Docker files and
o o
directories - /etc/sysconfig/docker
1.1.14 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd
1.1.15 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd-shim
1.1.16 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd-shim-runc-v1
1.1.17 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd-shim-runc-v2
1.1.18 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/runc
Page 277
Internal Only - General
Recommendation Set
Correctly
Yes No
2.3 Ensure the logging level is set to 'info' o o
2.5 Ensure insecure registries are not used o o
2.8 Ensure TLS authentication for Docker daemon is
o o
configured
2.14 Ensure centralized and remote logging is configured o o
2.17 Ensure Userland Proxy is Disabled o o
3.2 Ensure that docker.service file permissions are
o o
appropriately set
3.4 Ensure that docker.socket file permissions are set to 644
o o
or more restrictive
3.6 Ensure that /etc/docker directory permissions are set to
o o
755 or more restrictively
3.8 Ensure that registry certificate file permissions are set to
o o
444 or more restrictively
3.10 Ensure that TLS CA certificate file permissions are set to
o o
444 or more restrictively
3.12 Ensure that the Docker server certificate file permissions
o o
are set to 444 or more restrictively
3.14 Ensure that the Docker server certificate key file
o o
permissions are set to 400
3.16 Ensure that the Docker socket file permissions are set to
o o
660 or more restrictively
3.18 Ensure that daemon.json file permissions are set to 644
o o
or more restrictive
3.20 Ensure that the /etc/default/docker file permissions are
o o
set to 644 or more restrictively
3.21 Ensure that the /etc/sysconfig/docker file permissions are
o o
set to 644 or more restrictively
3.24 Ensure that the Containerd socket file permissions are
o o
set to 660 or more restrictively
4.2 Ensure that containers use only trusted base images o o
4.3 Ensure that unnecessary packages are not installed in
o o
the container
4.4 Ensure images are scanned and rebuilt to include
o o
security patches
Page 278
Internal Only - General
Recommendation Set
Correctly
Yes No
4.6 Ensure that HEALTHCHECK instructions have been
o o
added to container images
4.7 Ensure update instructions are not used alone in
o o
Dockerfiles
4.9 Ensure that COPY is used instead of ADD in Dockerfiles o o
4.11 Ensure only verified packages are installed o o
4.12 Ensure all signed artifacts are validated o o
5.1 Ensure swarm mode is not Enabled, if not needed o o
5.2 Ensure that, if applicable, an AppArmor Profile is enabled o o
5.3 Ensure that, if applicable, SELinux security options are
o o
set
5.4 Ensure that Linux kernel capabilities are restricted within
o o
containers
5.7 Ensure sshd is not run within containers o o
5.8 Ensure privileged ports are not mapped within containers o o
5.9 Ensure that only needed ports are open on the container o o
5.13 Ensure that the container's root filesystem is mounted as
o o
read only
5.15 Ensure that the 'on-failure' container restart policy is set
o o
to '5'
5.16 Ensure that the host's process namespace is not shared o o
5.17 Ensure that the host's IPC namespace is not shared o o
5.19 Ensure that the default ulimit is overwritten at runtime if
o o
needed
5.21 Ensure that the host's UTS namespace is not shared o o
5.22 Ensure the default seccomp profile is not Disabled o o
5.25 Ensure that cgroup usage is confirmed o o
5.27 Ensure that container health is checked at runtime o o
5.28 Ensure that Docker commands always make use of the
o o
latest version of their image
5.29 Ensure that the PIDs cgroup limit is used o o
5.31 Ensure that the host's user namespaces are not shared o o
6.1 Ensure that image sprawl is avoided o o
Page 279
Internal Only - General
Recommendation Set
Correctly
Yes No
6.2 Ensure that container sprawl is avoided o o
7.1 Ensure that the minimum number of manager nodes
o o
have been created in a swarm
7.3 Ensure that all Docker swarm overlay networks are
o o
encrypted
7.4 Ensure that Docker's secret management commands are
o o
used for managing secrets in a swarm cluster
7.5 Ensure that swarm manager is run in auto-lock mode o o
7.6 Ensure that the swarm manager auto-lock key is rotated
o o
periodically
7.7 Ensure that node certificates are rotated as appropriate o o
7.8 Ensure that CA certificates are rotated as appropriate o o
7.9 Ensure that management plane traffic is separated from
o o
data plane traffic
Page 280
Internal Only - General
Appendix: CIS Controls v7 Unmapped
Recommendations
Recommendation Set
Correctly
Yes No
5.30 Ensure that Docker's default bridge "docker0" is not used o o
Page 281
Internal Only - General
Appendix: CIS Controls v8 IG 1 Mapped
Recommendations
Recommendation Set
Correctly
Yes No
1.1.2 Ensure only trusted users are allowed to control Docker
o o
daemon
1.1.3 Ensure auditing is configured for the Docker daemon o o
2.1 Run the Docker daemon as a non-root user, if possible o o
2.14 Ensure centralized and remote logging is configured o o
2.15 Ensure containers are restricted from acquiring new
o o
privileges
3.1 Ensure that the docker.service file ownership is set to
o o
root:root
3.2 Ensure that docker.service file permissions are
o o
appropriately set
3.3 Ensure that docker.socket file ownership is set to
o o
root:root
3.4 Ensure that docker.socket file permissions are set to 644
o o
or more restrictive
3.5 Ensure that the /etc/docker directory ownership is set to
o o
root:root
3.6 Ensure that /etc/docker directory permissions are set to
o o
755 or more restrictively
3.7 Ensure that registry certificate file ownership is set to
o o
root:root
3.8 Ensure that registry certificate file permissions are set to
o o
444 or more restrictively
3.9 Ensure that TLS CA certificate file ownership is set to
o o
root:root
3.10 Ensure that TLS CA certificate file permissions are set to
o o
444 or more restrictively
3.11 Ensure that Docker server certificate file ownership is set
o o
to root:root
3.12 Ensure that the Docker server certificate file permissions
o o
are set to 444 or more restrictively
Page 282
Internal Only - General
Recommendation Set
Correctly
Yes No
3.13 Ensure that the Docker server certificate key file
o o
ownership is set to root:root
3.14 Ensure that the Docker server certificate key file
o o
permissions are set to 400
3.15 Ensure that the Docker socket file ownership is set to
o o
root:docker
3.16 Ensure that the Docker socket file permissions are set to
o o
660 or more restrictively
3.17 Ensure that the daemon.json file ownership is set to
o o
root:root
3.18 Ensure that daemon.json file permissions are set to 644
o o
or more restrictive
3.19 Ensure that the /etc/default/docker file ownership is set to
o o
root:root
3.20 Ensure that the /etc/default/docker file permissions are
o o
set to 644 or more restrictively
3.21 Ensure that the /etc/sysconfig/docker file permissions are
o o
set to 644 or more restrictively
3.22 Ensure that the /etc/sysconfig/docker file ownership is set
o o
to root:root
3.23 Ensure that the Containerd socket file ownership is set to
o o
root:root
3.24 Ensure that the Containerd socket file permissions are
o o
set to 660 or more restrictively
4.8 Ensure setuid and setgid permissions are removed o o
4.11 Ensure only verified packages are installed o o
5.5 Ensure that privileged containers are not used o o
5.14 Ensure that incoming container traffic is bound to a
o o
specific host interface
5.18 Ensure that host devices are not directly exposed to
o o
containers
5.22 Ensure the default seccomp profile is not Disabled o o
5.23 Ensure that docker exec commands are not used with
o o
the privileged option
Page 283
Internal Only - General
Recommendation Set
Correctly
Yes No
5.24 Ensure that docker exec commands are not used with
o o
the user=root option
5.25 Ensure that cgroup usage is confirmed o o
5.26 Ensure that the container is restricted from acquiring
o o
additional privileges
5.32 Ensure that the Docker socket is not mounted inside any
o o
containers
7.2 Ensure that swarm services are bound to a specific host
o o
interface
7.6 Ensure that the swarm manager auto-lock key is rotated
o o
periodically
7.7 Ensure that node certificates are rotated as appropriate o o
7.8 Ensure that CA certificates are rotated as appropriate o o
Page 284
Internal Only - General
Appendix: CIS Controls v8 IG 2 Mapped
Recommendations
Recommendation Set
Correctly
Yes No
1.1.1 Ensure a separate partition for containers has been
o o
created
1.1.2 Ensure only trusted users are allowed to control Docker
o o
daemon
1.1.3 Ensure auditing is configured for the Docker daemon o o
1.1.4 Ensure auditing is configured for Docker files and
o o
directories - /run/containerd
1.1.5 Ensure auditing is configured for Docker files and
o o
directories - /var/lib/docker
1.1.6 Ensure auditing is configured for Docker files and
o o
directories - /etc/docker
1.1.7 Ensure auditing is configured for Docker files and
o o
directories - docker.service
1.1.8 Ensure auditing is configured for Docker files and
o o
directories - containerd.sock
1.1.9 Ensure auditing is configured for Docker files and
o o
directories - docker.sock
1.1.10 Ensure auditing is configured for Docker files and
o o
directories - /etc/default/docker
1.1.11 Ensure auditing is configured for Docker files and
o o
directories - /etc/docker/daemon.json
1.1.12 Ensure auditing is configured for Docker files and
o o
directories - /etc/containerd/config.toml
1.1.13 Ensure auditing is configured for Docker files and
o o
directories - /etc/sysconfig/docker
1.1.14 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd
1.1.15 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd-shim
1.1.16 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd-shim-runc-v1
Page 285
Internal Only - General
Recommendation Set
Correctly
Yes No
1.1.17 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd-shim-runc-v2
1.1.18 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/runc
1.2.1 Ensure the container host has been Hardened o o
1.2.2 Ensure that the version of Docker is up to date o o
2.1 Run the Docker daemon as a non-root user, if possible o o
2.2 Ensure network traffic is restricted between containers on
o o
the default bridge
2.3 Ensure the logging level is set to 'info' o o
2.4 Ensure Docker is allowed to make changes to iptables o o
2.5 Ensure insecure registries are not used o o
2.8 Ensure TLS authentication for Docker daemon is
o o
configured
2.9 Ensure the default ulimit is configured appropriately o o
2.12 Ensure base device size is not changed until needed o o
2.14 Ensure centralized and remote logging is configured o o
2.15 Ensure containers are restricted from acquiring new
o o
privileges
2.16 Ensure live restore is enabled o o
2.17 Ensure Userland Proxy is Disabled o o
2.19 Ensure that experimental features are not implemented
o o
in production
3.1 Ensure that the docker.service file ownership is set to
o o
root:root
3.2 Ensure that docker.service file permissions are
o o
appropriately set
3.3 Ensure that docker.socket file ownership is set to
o o
root:root
3.4 Ensure that docker.socket file permissions are set to 644
o o
or more restrictive
3.5 Ensure that the /etc/docker directory ownership is set to
o o
root:root
Page 286
Internal Only - General
Recommendation Set
Correctly
Yes No
3.6 Ensure that /etc/docker directory permissions are set to
o o
755 or more restrictively
3.7 Ensure that registry certificate file ownership is set to
o o
root:root
3.8 Ensure that registry certificate file permissions are set to
o o
444 or more restrictively
3.9 Ensure that TLS CA certificate file ownership is set to
o o
root:root
3.10 Ensure that TLS CA certificate file permissions are set to
o o
444 or more restrictively
3.11 Ensure that Docker server certificate file ownership is set
o o
to root:root
3.12 Ensure that the Docker server certificate file permissions
o o
are set to 444 or more restrictively
3.13 Ensure that the Docker server certificate key file
o o
ownership is set to root:root
3.14 Ensure that the Docker server certificate key file
o o
permissions are set to 400
3.15 Ensure that the Docker socket file ownership is set to
o o
root:docker
3.16 Ensure that the Docker socket file permissions are set to
o o
660 or more restrictively
3.17 Ensure that the daemon.json file ownership is set to
o o
root:root
3.18 Ensure that daemon.json file permissions are set to 644
o o
or more restrictive
3.19 Ensure that the /etc/default/docker file ownership is set to
o o
root:root
3.20 Ensure that the /etc/default/docker file permissions are
o o
set to 644 or more restrictively
3.21 Ensure that the /etc/sysconfig/docker file permissions are
o o
set to 644 or more restrictively
3.22 Ensure that the /etc/sysconfig/docker file ownership is set
o o
to root:root
3.23 Ensure that the Containerd socket file ownership is set to
o o
root:root
Page 287
Internal Only - General
Recommendation Set
Correctly
Yes No
3.24 Ensure that the Containerd socket file permissions are
o o
set to 660 or more restrictively
4.2 Ensure that containers use only trusted base images o o
4.3 Ensure that unnecessary packages are not installed in
o o
the container
4.4 Ensure images are scanned and rebuilt to include
o o
security patches
4.7 Ensure update instructions are not used alone in
o o
Dockerfiles
4.8 Ensure setuid and setgid permissions are removed o o
4.9 Ensure that COPY is used instead of ADD in Dockerfiles o o
4.11 Ensure only verified packages are installed o o
5.1 Ensure swarm mode is not Enabled, if not needed o o
5.2 Ensure that, if applicable, an AppArmor Profile is enabled o o
5.3 Ensure that, if applicable, SELinux security options are
o o
set
5.4 Ensure that Linux kernel capabilities are restricted within
o o
containers
5.5 Ensure that privileged containers are not used o o
5.7 Ensure sshd is not run within containers o o
5.10 Ensure that the host's network namespace is not shared o o
5.11 Ensure that the memory usage for containers is limited o o
5.12 Ensure that CPU priority is set appropriately on
o o
containers
5.14 Ensure that incoming container traffic is bound to a
o o
specific host interface
5.16 Ensure that the host's process namespace is not shared o o
5.17 Ensure that the host's IPC namespace is not shared o o
5.18 Ensure that host devices are not directly exposed to
o o
containers
5.19 Ensure that the default ulimit is overwritten at runtime if
o o
needed
5.21 Ensure that the host's UTS namespace is not shared o o
5.22 Ensure the default seccomp profile is not Disabled o o
Page 288
Internal Only - General
Recommendation Set
Correctly
Yes No
5.23 Ensure that docker exec commands are not used with
o o
the privileged option
5.24 Ensure that docker exec commands are not used with
o o
the user=root option
5.25 Ensure that cgroup usage is confirmed o o
5.26 Ensure that the container is restricted from acquiring
o o
additional privileges
5.27 Ensure that container health is checked at runtime o o
5.30 Ensure that Docker's default bridge "docker0" is not used o o
5.31 Ensure that the host's user namespaces are not shared o o
5.32 Ensure that the Docker socket is not mounted inside any
o o
containers
6.1 Ensure that image sprawl is avoided o o
6.2 Ensure that container sprawl is avoided o o
7.2 Ensure that swarm services are bound to a specific host
o o
interface
7.3 Ensure that all Docker swarm overlay networks are
o o
encrypted
7.5 Ensure that swarm manager is run in auto-lock mode o o
7.6 Ensure that the swarm manager auto-lock key is rotated
o o
periodically
7.7 Ensure that node certificates are rotated as appropriate o o
7.8 Ensure that CA certificates are rotated as appropriate o o
7.9 Ensure that management plane traffic is separated from
o o
data plane traffic
Page 289
Internal Only - General
Appendix: CIS Controls v8 IG 3 Mapped
Recommendations
Recommendation Set
Correctly
Yes No
1.1.1 Ensure a separate partition for containers has been
o o
created
1.1.2 Ensure only trusted users are allowed to control Docker
o o
daemon
1.1.3 Ensure auditing is configured for the Docker daemon o o
1.1.4 Ensure auditing is configured for Docker files and
o o
directories - /run/containerd
1.1.5 Ensure auditing is configured for Docker files and
o o
directories - /var/lib/docker
1.1.6 Ensure auditing is configured for Docker files and
o o
directories - /etc/docker
1.1.7 Ensure auditing is configured for Docker files and
o o
directories - docker.service
1.1.8 Ensure auditing is configured for Docker files and
o o
directories - containerd.sock
1.1.9 Ensure auditing is configured for Docker files and
o o
directories - docker.sock
1.1.10 Ensure auditing is configured for Docker files and
o o
directories - /etc/default/docker
1.1.11 Ensure auditing is configured for Docker files and
o o
directories - /etc/docker/daemon.json
1.1.12 Ensure auditing is configured for Docker files and
o o
directories - /etc/containerd/config.toml
1.1.13 Ensure auditing is configured for Docker files and
o o
directories - /etc/sysconfig/docker
1.1.14 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd
1.1.15 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd-shim
1.1.16 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd-shim-runc-v1
Page 290
Internal Only - General
Recommendation Set
Correctly
Yes No
1.1.17 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/containerd-shim-runc-v2
1.1.18 Ensure auditing is configured for Docker files and
o o
directories - /usr/bin/runc
1.2.1 Ensure the container host has been Hardened o o
1.2.2 Ensure that the version of Docker is up to date o o
2.1 Run the Docker daemon as a non-root user, if possible o o
2.2 Ensure network traffic is restricted between containers on
o o
the default bridge
2.3 Ensure the logging level is set to 'info' o o
2.4 Ensure Docker is allowed to make changes to iptables o o
2.5 Ensure insecure registries are not used o o
2.8 Ensure TLS authentication for Docker daemon is
o o
configured
2.9 Ensure the default ulimit is configured appropriately o o
2.12 Ensure base device size is not changed until needed o o
2.14 Ensure centralized and remote logging is configured o o
2.15 Ensure containers are restricted from acquiring new
o o
privileges
2.16 Ensure live restore is enabled o o
2.17 Ensure Userland Proxy is Disabled o o
2.19 Ensure that experimental features are not implemented
o o
in production
3.1 Ensure that the docker.service file ownership is set to
o o
root:root
3.2 Ensure that docker.service file permissions are
o o
appropriately set
3.3 Ensure that docker.socket file ownership is set to
o o
root:root
3.4 Ensure that docker.socket file permissions are set to 644
o o
or more restrictive
3.5 Ensure that the /etc/docker directory ownership is set to
o o
root:root
Page 291
Internal Only - General
Recommendation Set
Correctly
Yes No
3.6 Ensure that /etc/docker directory permissions are set to
o o
755 or more restrictively
3.7 Ensure that registry certificate file ownership is set to
o o
root:root
3.8 Ensure that registry certificate file permissions are set to
o o
444 or more restrictively
3.9 Ensure that TLS CA certificate file ownership is set to
o o
root:root
3.10 Ensure that TLS CA certificate file permissions are set to
o o
444 or more restrictively
3.11 Ensure that Docker server certificate file ownership is set
o o
to root:root
3.12 Ensure that the Docker server certificate file permissions
o o
are set to 444 or more restrictively
3.13 Ensure that the Docker server certificate key file
o o
ownership is set to root:root
3.14 Ensure that the Docker server certificate key file
o o
permissions are set to 400
3.15 Ensure that the Docker socket file ownership is set to
o o
root:docker
3.16 Ensure that the Docker socket file permissions are set to
o o
660 or more restrictively
3.17 Ensure that the daemon.json file ownership is set to
o o
root:root
3.18 Ensure that daemon.json file permissions are set to 644
o o
or more restrictive
3.19 Ensure that the /etc/default/docker file ownership is set to
o o
root:root
3.20 Ensure that the /etc/default/docker file permissions are
o o
set to 644 or more restrictively
3.21 Ensure that the /etc/sysconfig/docker file permissions are
o o
set to 644 or more restrictively
3.22 Ensure that the /etc/sysconfig/docker file ownership is set
o o
to root:root
3.23 Ensure that the Containerd socket file ownership is set to
o o
root:root
Page 292
Internal Only - General
Recommendation Set
Correctly
Yes No
3.24 Ensure that the Containerd socket file permissions are
o o
set to 660 or more restrictively
4.2 Ensure that containers use only trusted base images o o
4.3 Ensure that unnecessary packages are not installed in
o o
the container
4.4 Ensure images are scanned and rebuilt to include
o o
security patches
4.6 Ensure that HEALTHCHECK instructions have been
o o
added to container images
4.7 Ensure update instructions are not used alone in
o o
Dockerfiles
4.8 Ensure setuid and setgid permissions are removed o o
4.9 Ensure that COPY is used instead of ADD in Dockerfiles o o
4.11 Ensure only verified packages are installed o o
4.12 Ensure all signed artifacts are validated o o
5.1 Ensure swarm mode is not Enabled, if not needed o o
5.2 Ensure that, if applicable, an AppArmor Profile is enabled o o
5.3 Ensure that, if applicable, SELinux security options are
o o
set
5.4 Ensure that Linux kernel capabilities are restricted within
o o
containers
5.5 Ensure that privileged containers are not used o o
5.7 Ensure sshd is not run within containers o o
5.8 Ensure privileged ports are not mapped within containers o o
5.9 Ensure that only needed ports are open on the container o o
5.10 Ensure that the host's network namespace is not shared o o
5.11 Ensure that the memory usage for containers is limited o o
5.12 Ensure that CPU priority is set appropriately on
o o
containers
5.13 Ensure that the container's root filesystem is mounted as
o o
read only
5.14 Ensure that incoming container traffic is bound to a
o o
specific host interface
5.16 Ensure that the host's process namespace is not shared o o
Page 293
Internal Only - General
Recommendation Set
Correctly
Yes No
5.17 Ensure that the host's IPC namespace is not shared o o
5.18 Ensure that host devices are not directly exposed to
o o
containers
5.19 Ensure that the default ulimit is overwritten at runtime if
o o
needed
5.21 Ensure that the host's UTS namespace is not shared o o
5.22 Ensure the default seccomp profile is not Disabled o o
5.23 Ensure that docker exec commands are not used with
o o
the privileged option
5.24 Ensure that docker exec commands are not used with
o o
the user=root option
5.25 Ensure that cgroup usage is confirmed o o
5.26 Ensure that the container is restricted from acquiring
o o
additional privileges
5.27 Ensure that container health is checked at runtime o o
5.30 Ensure that Docker's default bridge "docker0" is not used o o
5.31 Ensure that the host's user namespaces are not shared o o
5.32 Ensure that the Docker socket is not mounted inside any
o o
containers
6.1 Ensure that image sprawl is avoided o o
6.2 Ensure that container sprawl is avoided o o
7.2 Ensure that swarm services are bound to a specific host
o o
interface
7.3 Ensure that all Docker swarm overlay networks are
o o
encrypted
7.5 Ensure that swarm manager is run in auto-lock mode o o
7.6 Ensure that the swarm manager auto-lock key is rotated
o o
periodically
7.7 Ensure that node certificates are rotated as appropriate o o
7.8 Ensure that CA certificates are rotated as appropriate o o
7.9 Ensure that management plane traffic is separated from
o o
data plane traffic
Page 294
Internal Only - General
Appendix: CIS Controls v8 Unmapped
Recommendations
Recommendation Set
Correctly
Yes No
No unmapped recommendations to CIS Controls v8 o o
Page 295
Internal Only - General
Appendix: Change History
Date Version Changes for this version
7/11/2025 V1.8.0 Added Support for Docker
28.x
7/9/2025 V1.8.0 Ticket # 24344
Updated recommendation
references to insecure
registries.
7/9/2025 V1.8.0 Ticket #23891
Corrected and improved the
overlapping verbiage and
recommendations 1.1.11
and 1.1.6
7/1/2025 V1.8.0 Ticket #23800
Improved static file location
audit and remediations with
standard docker variable
names i.e. data-root
7/1/2025 V1.8.0 Ticket #23140
Edited and improved the
audit method for evaluating
runtime flags.
7/11/2024 V1.7.0 Added Support for Docker
26.x
7/9/2024 V1.7.0 Ticket #19871
Reviewed Swarm section 7
and recommendations
referencing Swarm in
Section 5.
7/6/2024 V1.7.0 Ticket #14454
Added recommendation that
adds /var/lib/docker to
critical audit paths
Page 296
Internal Only - General
Date Version Changes for this version
6/14/2023 V1.6.0 Added Support for CIS-CAT
Automated Assesment
Content
6/1/2023 V1.6.0 Ticket # 18844
Updated remediation for
adding audit.rules
6/1/2023 V1.6.0 Added Support for Docker
v24
Page 297
Internal Only - General
12/02/2022 V1.5.0 Ticket # 17161 updated
recommendation 2.5 to
improve clarity and
grammar.
12/02/2022 1.5.0 Ticket # 17160 updated
recommendation 1.1.17 to
refer to proper file
10/11/2022 1.5.0 Ticket # 17187 Updated
order of recommendations
to provide more logical flow.
10/11/2022 1.5.0 Ticket # 17188 updated
recommendation 4.1 by
editing grammar.
09/01/2022 1.5.0 Ticket # 16868
2/13/2022 1.4.0 Ticket # 15017 updated
overview to reference the
new Docker version
20.10.12 included in the
benchmark
2/10/2022 1.4.0 Ticket # 15016 added
recommendation “Ensure all
signed artifacts are
validated”.
09/23/2021 1.3.0 Ticket #12321 reorganized
and renamed sections
09/22/2021 1.3.0 Ticket # 12525 updated
recommendation 3.3 to
remove out of date
reference
09/22/2021 1.3.0 Ticket # 12004 updated
recommendation 1.1.15
added shimrunc-v1/v2
Page 298
Internal Only - General
9/01/2021 1.3.0 Ticket # 10896 updated
recommendation 3.8 to stat
for the file and not *
8/28/2021 1.3.0 Ticket # 11932 realigned
milestones
8/28/2021 1.3.0 Ticket # 10849 updated
recommendation 1.1.5 to
correct recursive and
excessive logging results.
Page 299
Internal Only - General
Reference in new issue View Git Blame Copy Permalink