--- os_desktop_enable: false os_env_extra_user_paths: [] os_auth_pw_max_age: 60 os_auth_pw_min_age: 7 # Discourage password cycling os_auth_retries: 5 os_auth_lockout_time: 600 # Seconds (600 = 10min) os_auth_timeout: 60 os_auth_allow_homeless: false os_auth_pam_passwdqc_enable: true os_auth_pam_passwdqc_options: 'min=disabled,disabled,16,12,8' # Used in RHEL6 os_auth_pam_pwquality_options: 'try_first_pass retry=3 authtok_type=' # Used in RHEL7 and RHEL8 os_auth_root_ttys: [console, tty1, tty2, tty3, tty4, tty5, tty6] os_chfn_restrict: '' # Set to false to disable chmod /home folders to 700 os_chmod_home_folders: true # May contain: change_user os_security_users_allow: [] # Specify user home folders in /home that shouldn't be chmodded to 700 os_ignore_home_folder_users: ['lost+found'] # Specify system accounts whose login should not be disabled and password not changed os_ignore_users: ['vagrant', 'kitchen'] os_security_kernel_enable_module_loading: true os_security_kernel_enable_core_dump: false os_security_suid_sgid_enforce: true # User-defined blacklist and whitelist os_security_suid_sgid_blacklist: [] os_security_suid_sgid_whitelist: [] # If this is true, remove any suid/sgid bits from files that are not in the whitelist os_security_suid_sgid_remove_from_unknown: false # Remove packages with known security issues os_security_packages_clean: true os_security_packages_list: ['xinetd', 'inetd', 'ypserv', 'telnet-server', 'rsh-server', 'prelink'] # Allow interactive startup (rhel, centos) os_security_init_prompt: true # Require root password for single user mode. (rhel, centos) os_security_init_single: false # Apply ufw defaults ufw_manage_defaults: true # Empty variable disables IPT_SYSCTL in /etc/default/ufw # By default in Ubuntu it is set to: /etc/ufw/sysctl.conf # CAUTION! # If you enable it - it overwrites /etc/sysctl.conf file, managed by hardening framework ufw_ipt_sysctl: '' # Default ufw variables ufw_default_input_policy: 'DROP' ufw_default_output_policy: 'ACCEPT' ufw_default_forward_policy: 'DROP' ufw_default_application_policy: 'SKIP' ufw_manage_builtins: 'no' ufw_ipt_modules: 'nf_conntrack_ftp nf_nat_ftp nf_conntrack_netbios_ns' # Set to true to apply rules to support IPv6 (no means only IPv6 on loopback # accepted). ufw_enable_ipv6: true sysctl_config: # These settings eliminate an entire class of security vulnerabilities: # time-of-check-time-of-use cross-privilege attacks using guessable # filenames (generally seen as "/tmp file race" vulnerabilities). fs.protected_hardlinks: 1 fs.protected_symlinks: 1 # Prevent core dumps with SUID. These are usually only # needed by developers and may contain sensitive information. | sysctl-31 fs.suid_dumpable: 0 # Controls whether core dumps will append the PID to the core filename # Useful for debugging multi-threaded applications kernel.core_uses_pid: 1 # When an attacker is trying to exploit the local kernel, it is often # helpful to be able to examine where in memory the kernel, modules, # and data structures live. As such, kernel addresses should be treated # as sensitive information. # # Many files and interfaces contain these addresses (e.g. /proc/kallsyms, # /proc/modules, etc), and this setting can censor the addresses. A value # of "0" allows all users to see the kernel addresses. A value of "1" # limits visibility to the root user, and "2" blocks even the root user. # # Some off-the-shelf malware exploit kernel addresses exposed # via /proc/kallsyms so by not making these addresses easily available # we increase the cost of such attack some what; now such malware has # to check which kernel Tails is running and then fetch the corresponding # kernel address map from some external source. This is not hard, # but certainly not all malware has such functionality. | Tails-2 kernel.kptr_restrict: 2 # kexec is dangerous: it enables replacement of the running kernel. | Tails-3 kernel.kexec_load_disabled: 1 # This setting controls how the kernel behaves towards module changes at # runtime. Setting to 1 will disable module loading at runtime. # Setting it to 0 is actually never supported. | sysctl-29 # kernel.modules_disabled: 1 # Magic Sysrq should be disabled, but can also be set to a safe value if so # desired for physical machines. It can allow a safe reboot if the system hangs # and is a 'cleaner' alternative to hitting the reset button. | sysctl-30 # The following values are permitted: # * **0** - disable sysrq # * **1** - enable sysrq completely # * **>1** - bitmask of enabled sysrq functions: # * **2** - control of console logging level # * **4** - control of keyboard (SAK, unraw) # * **8** - debugging dumps of processes etc. # * **16** - sync command # * **32** - remount read-only # * **64** - signalling of processes (term, kill, oom-kill) # * **128** - reboot/poweroff # * **256** - nicing of all RT tasks kernel.sysrq: 0 # Virtual memory regions protection | sysctl-32 kernel.randomize_va_space: 2 # The PTRACE system is used for debugging. With it, a single user process # can attach to any other dumpable process owned by the same user. In the # case of malicious software, it is possible to use PTRACE to access # credentials that exist in memory (re-using existing SSH connections, # extracting GPG agent information, etc). # # A PTRACE scope of "0" is the more permissive mode. A scope of "1" limits # PTRACE only to direct child processes (e.g. "gdb name-of-program" and # "strace -f name-of-program" work, but gdb's "attach" and "strace -fp $PID" # do not). The PTRACE scope is ignored when a user has CAP_SYS_PTRACE, so # "sudo strace -fp $PID" will work as before. For more details see: # https://wiki.ubuntu.com/SecurityTeam/Roadmap/KernelHardening#ptrace # # For applications launching crash handlers that need PTRACE, exceptions can # be registered by the debugee by declaring in the segfault handler # specifically which process will be using PTRACE on the debugee: # prctl(PR_SET_PTRACER, debugger_pid, 0, 0, 0); # # In general, PTRACE is not needed for the average running Ubuntu system. # To that end, the default is to set the PTRACE scope to "1". This value # may not be appropriate for developers or servers with only admin accounts. # kernel.yama.ptrace_scope = 1 kernel.yama.ptrace_scope: 1 # Disable traffic forwarding. # Setting the flag to 0 ensures that a system with multiple interfaces (for example, a hard # proxy), will never be able to forward packets, and therefore, never serve as a router. # | sysctl-01 | sysctl-19 net.ipv4.ip_forward: 0 net.ipv6.conf.all.forwarding: 0 # Enable RFC-recommended source validation feature. # If the return packet does not go out the same interface that the corresponding # source packet came from, the packet is dropped (and logged if log_martians is set). # | sysctl-02 net.ipv4.conf.all.rp_filter: 1 net.ipv4.conf.default.rp_filter: 1 # Reduce the surface on SMURF attacks. | sysctl-04 # Make sure to ignore ECHO broadcasts, which are only required in broad network analysis. net.ipv4.icmp_echo_ignore_broadcasts: 1 # Some routers (and some attackers) will send responses that violate RFC-1122 and attempt # to fill up a log file system with many useless error messages. # | sysctl-03 net.ipv4.icmp_ignore_bogus_error_responses: 1 # Limit the amount of traffic the system uses for ICMP. | sysctl-05 net.ipv4.icmp_ratelimit: 100 # Adjust the ICMP ratelimit to include ping, dst unreachable, # source quench, ime exceed, param problem, timestamp reply, information reply | sysctl-06 net.ipv4.icmp_ratemask: 88089 # Disable TCP timestamps in order to not reveal system uptime. | sysctl-07 net.ipv4.tcp_timestamps: 0 # Define restriction level for announcing the local source IP | sysctl-08 net.ipv4.conf.all.arp_ignore: 1 # Define mode for sending replies in response to # received ARP requests that resolve local target IP addresses | sysctl-09 net.ipv4.conf.all.arp_announce: 2 # RFC 1337 fix F1 | sysctl-10 net.ipv4.tcp_rfc1337: 1 # Attackers use SYN flood attacks to perform a denial of service attack on a system # by sending many SYN packets without completing the three way handshake. # This will quickly use up slots in the kernel's half-open connection queue and # prevent legitimate connections from succeeding. # SYN cookies allow the system to keep accepting valid connections, even if # under a denial of service attack. CIS Distro Independent 3.2.8. net.ipv4.tcp_syncookies: 1 # Send(router) or accept(host) RFC1620 shared media redirects | sysctl-12 net.ipv4.conf.all.shared_media: 1 net.ipv4.conf.default.shared_media: 1 # Accepting source route can lead to malicious networking behavior, # so disable it if not needed. | sysctl-13 net.ipv4.conf.all.accept_source_route: 0 net.ipv4.conf.default.accept_source_route: 0 net.ipv6.conf.all.accept_source_route: 0 net.ipv6.conf.default.accept_source_route: 0 # For non-routers: don't send redirects. # An attacker could use a compromised host to send invalid ICMP redirects to other # router devices in an attempt to corrupt routing and have users access a system # set up by the attacker as opposed to a valid system. # | sysctl-16 net.ipv4.conf.all.send_redirects: 0 net.ipv4.conf.default.send_redirects: 0 # Log martian packets # This feature logs packets with un-routable source addresses to the kernel log. # Enabling this feature and logging these packets allows an administrator to investigate # the possibility that an attacker is sending spoofed packets to their system. # | sysctl-17 net.ipv4.conf.all.log_martians: 1 net.ipv4.conf.default.log_martians: 1 # Accepting redirects can lead to malicious networking behavior, so disable # it if not needed. # Attackers could use bogus ICMP redirect messages to maliciously alter the system # routing tables and get them to send packets to incorrect networks and allow # your system packets to be captured. # Setting net.ipv4.conf.all.secure_redirects to 0 protects the system from # routing table updates by possibly compromised known gateways. # | sysctl-13 | sysctl-14 | sysctl-15 | sysctl-20 net.ipv4.conf.default.accept_redirects: 0 net.ipv4.conf.all.accept_redirects: 0 net.ipv4.conf.all.secure_redirects: 0 net.ipv4.conf.default.secure_redirects: 0 net.ipv6.conf.default.accept_redirects: 0 net.ipv6.conf.all.accept_redirects: 0 # Ignore RAs on Ipv6. | sysctl-25 net.ipv6.conf.all.accept_ra: 0 net.ipv6.conf.default.accept_ra: 0 # Disable acceptance of IPv6 router solicitations messages | sysctl-21 net.ipv6.conf.default.router_solicitations: 0 # Disable Accept Router Preference from router advertisement | sysctl-22 net.ipv6.conf.default.accept_ra_rtr_pref: 0 # Disable learning Prefix Information from router advertisement | sysctl-23 net.ipv6.conf.default.accept_ra_pinfo: 0 # Disable learning Hop limit from router advertisement | sysctl-24 net.ipv6.conf.default.accept_ra_defrtr: 0 # Disable IPv6 autoconfiguration | sysctl-26 net.ipv6.conf.default.autoconf: 0 # Disable neighbor solicitations to send out per address | sysctl-27 net.ipv6.conf.default.dad_transmits: 0 # Assign one global unicast IPv6 addresses to each interface | sysctl-28 net.ipv6.conf.default.max_addresses: 1 # Protect the zero page of memory from userspace mmap to prevent kernel # NULL-dereference attacks against potential future kernel security # vulnerabilities. (Added in kernel 2.6.23.) # # While this default is built into the Ubuntu kernel, there is no way to # restore the kernel default if the value is changed during runtime; for # example via package removal (e.g. wine, dosemu). Therefore, this value # is reset to the secure default each time the sysctl values are loaded. vm.mmap_min_addr: 65536 # These settings are set to the maximum supported value in order to # improve ASLR effectiveness for mmap, at the cost of increased # address-space fragmentation. | Tail-1 vm.mmap_rnd_bits: 32 vm.mmap_rnd_compat_bits: 16 # Do not delete the following line or otherwise the playbook will fail # at task 'create a combined sysctl-dict if overwrites are defined' sysctl_overwrite: # Disable unused filesystems os_unused_filesystems: - "cramfs" - "freevxfs" - "jffs2" - "hfs" - "hfsplus" - "squashfs" - "udf" - "vfat" # Obsolete network protocols that should be disabled # per CIS Oracle Linux 6 Benchmark (2016) - "dccp" # CIS 3.5.1 - "rds" # CIS 3.5.3 - "sctp" # CIS 3.5.2 - "tipc" # CIS 3.5.4 # Whitelist for used filesystems os_filesystem_whitelist: [] # Set to false to turn the role into a no-op. Useful when using # the Ansible role dependency mechanism. os_hardening_enabled: true # Set to false to disable installing and configuring auditd. os_auditd_enabled: true os_auditd_max_log_file: 6 os_auditd_max_log_file_action: keep_logs # Set the SELinux state, which can be either disabled, permissive, or enforcing. os_selinux_state: enforcing # Set the SELinux polixy. os_selinux_policy: targeted # Mount options for proc in /etc/fstab. proc_mnt_options: 'rw,nosuid,nodev,noexec,relatime,hidepid={{ hidepid_option }}' # Set to false to disable installing and configuring cron. os_cron_enabled: true # Set to false to disable installing and configuring limits. os_limits_enabled: true # Set to false to disable installing and configuring login_defs. os_login_defs_enabled: true # Set to false to disable installing and configuring minimize_access. os_minimize_access_enabled: true # Set to false to disable installing and configuring pam. os_pam_enabled: true # Set to false to disable installing and configuring modprobe. os_modprobe_enabled: true # Set to false to disable installing and configuring profile. os_profile_enabled: true # Set to false to disable installing and configuring securetty. os_securetty_enabled: true # Set to false to disable installing and configuring sysctl. os_sysctl_enabled: true # Set to false to disable installing and configuring user_accounts. os_user_accounts_enabled: true # Set to false to disable installing and configuring rhosts. os_rhosts_enabled: true # Set to false to disable installing and configuring yum. os_yum_enabled: true # Set to false to disable installing and configuring apt. os_apt_enabled: true # Set to false to disable installing and configuring selinux. os_selinux_enabled: true # Define the number of SHA rounds. # With a lot of rounds brute forcing the password is more difficult. But note also that it more CPU resources will be needed to authenticate users. # The values must be inside the 1000-999999999 range. os_sha_crypt_min_rounds: "640000" os_sha_crypt_max_rounds: "640000"