Guide to the Secure Configuration of Red Hat Enterprise Linux 8
Rules, Groups, and Values defined within the XCCDF Benchmark
-
Account Lockouts Must Be Logged
PAM faillock locks an account due to excessive password failures, this event must be logged.Rule Medium Severity -
Account Lockouts Must Persist
By setting a `dir` in the faillock configuration account lockouts will persist across reboots.Rule Medium Severity -
Limit Password Reuse: system-auth
Do not allow users to reuse recent passwords. This can be accomplished by using the <code>remember</code> option for the <code>pam_pwhistory</code> PAM module. <br> <br> On systems with n...Rule Medium Severity -
Limit Password Reuse
Do not allow users to reuse recent passwords. This can be accomplished by using theremember
option for thepam_unix
orpam_pwhistory
PAM modules.Rule Medium Severity -
Account Lockouts Must Be Logged
PAM faillock locks an account due to excessive password failures, this event must be logged.Rule Medium Severity -
Configure the root Account for Failed Password Attempts
This rule configures the system to lock out the <code>root</code> account after a number of incorrect login attempts using <code>pam_faillock.so</code>. pam_faillock.so module requires multiple en...Rule Medium Severity -
Lock Accounts Must Persist
This rule ensures that the system lock out accounts using <code>pam_faillock.so</code> persist after system reboot. From "pam_faillock" man pages: <pre>Note that the default directory that "pam_fai...Rule Medium Severity -
Enforce pam_faillock for Local Accounts Only
The pam_faillock module's <code>local_users_only</code> parameter controls requirements for enforcing failed lockout attempts only for local user accounts and ignoring centralized user account mana...Rule Medium Severity -
Set Interval For Counting Failed Password Attempts
Utilizing <code>pam_faillock.so</code>, the <code>fail_interval</code> directive configures the system to lock out an account after a number of incorrect login attempts within a specified time peri...Rule Medium Severity -
Do Not Show System Messages When Unsuccessful Logon Attempts Occur
This rule ensures the system prevents informative messages from being presented to the user pertaining to logon information after a number of incorrect login attempts using <code>pam_faillock.so</c...Rule Medium Severity -
Set Password Quality Requirements
The default <code>pam_pwquality</code> PAM module provides strength checking for passwords. It performs a number of checks, such as making sure passwords are not similar to dictionary words, are of...Group -
dcredit
Minimum number of digits in passwordValue -
dictcheck
Prevent the use of dictionary words for passwords.Value -
difok
Minimum number of characters not present in old passwordValue -
lcredit
Minimum number of lower case in passwordValue -
maxclassrepeat
Maximum Number of Consecutive Repeating Characters in a Password From the Same Character ClassValue -
maxrepeat
Maximum Number of Consecutive Repeating Characters in a PasswordValue -
minclass
Minimum number of categories of characters that must exist in a passwordValue -
minlen
Minimum number of characters in passwordValue -
ocredit
Minimum number of other (special characters) in passwordValue -
retry
Number of retry attempts before erroring outValue -
ucredit
Minimum number of upper case in passwordValue -
Ensure PAM Enforces Password Requirements - Prevent the Use of Dictionary Words
The pam_pwquality module'sdictcheck
check if passwords contains dictionary words. Whendictcheck
is set to1
passwords will be checked for dictionary words.Rule Medium Severity -
Ensure PAM Enforces Password Requirements - Enforce for Local Accounts Only
The pam_pwquality module's <code>local_users_only</code> parameter controls requirements for enforcing password complexity by pam_pwquality only for local user accounts and ignoring centralized use...Rule Medium Severity -
Ensure PAM Enforces Password Requirements - Enforce for root User
The pam_pwquality module's <code>enforce_for_root</code> parameter controls requirements for enforcing password complexity for the root user. Enable the <code>enforce_for_root</code> setting in <co...Rule Medium Severity -
Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
The pam_pwquality module's <code>lcredit</code> parameter controls requirements for usage of lowercase letters in a password. When set to a negative number, any password will be required to contain...Rule Medium Severity -
Ensure PAM Enforces Password Requirements - Maximum Consecutive Repeating Characters from Same Character Class
The pam_pwquality module's <code>maxclassrepeat</code> parameter controls requirements for consecutive repeating characters from the same character class. When set to a positive number, it will rej...Rule Medium Severity -
Ensure PAM password complexity module is enabled in password-auth
To enable PAM password complexity in password-auth file: Edit the <code>password</code> section in <code>/etc/pam.d/password-auth</code> to show <code>password requisite ...Rule Medium Severity -
Ensure PAM password complexity module is enabled in system-auth
To enable PAM password complexity in system-auth file: Edit the <code>password</code> section in <code>/etc/pam.d/system-auth</code> to show <code>password requisite ...Rule Medium Severity -
Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted Per-Session
To configure the number of retry prompts that are permitted per-session: Edit the <code>/etc/security/pwquality.conf</code> to include <code>retry=<xccdf-1.2:sub idref="xccdf_org.ssgproject.conte...Rule Medium Severity -
Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
The pam_pwquality module's <code>ucredit=</code> parameter controls requirements for usage of uppercase letters in a password. When set to a negative number, any password will be required to contai...Rule Medium Severity -
Set Password Hashing Algorithm
The system's default algorithm for storing password hashes in/etc/shadow
is SHA-512. This can be configured in several locations.Group -
Set Password Hashing Algorithm in /etc/libuser.conf
In <code>/etc/libuser.conf</code>, add or correct the following line in its <code>[defaults]</code> section to ensure the system will use the <xccdf-1.2:sub idref="xccdf_org.ssgproject.content_valu...Rule Medium Severity -
Set Password Hashing Rounds in /etc/login.defs
In <code>/etc/login.defs</code>, ensure <code>SHA_CRYPT_MIN_ROUNDS</code> and <code>SHA_CRYPT_MAX_ROUNDS</code> has the minimum value of <code>5000</code>. For example: <pre>SHA_CRYPT_MIN_ROUNDS 50...Rule Medium Severity -
Protect Physical Console Access
It is impossible to fully protect a system from an attacker with physical access, so securing the space in which the system is located should be considered a necessary step. However, there are some...Group -
Login timeout for idle sessions
Specify duration of allowed idle time.Value -
Disable debug-shell SystemD Service
SystemD's <code>debug-shell</code> service is intended to diagnose SystemD related boot issues with various <code>systemctl</code> commands. Once enabled and following a system reboot, the root she...Rule Medium Severity -
Disable Ctrl-Alt-Del Burst Action
By default, <code>SystemD</code> will reboot the system if the <code>Ctrl-Alt-Del</code> key sequence is pressed Ctrl-Alt-Delete more than 7 times in 2 seconds. <br> <br> To configure the s...Rule High Severity -
Disable Ctrl-Alt-Del Reboot Activation
By default, <code>SystemD</code> will reboot the system if the <code>Ctrl-Alt-Del</code> key sequence is pressed. <br> <br> To configure the system to ignore the <code>Ctrl-Alt-Del</code> k...Rule High Severity -
Configure tmux to lock session after inactivity
To enable console screen locking in <code>tmux</code> terminal multiplexer after a period of inactivity, the <code>lock-after-time</code> option has to be set to a value greater than 0 and less tha...Rule Medium Severity -
Configure Logind to terminate idle sessions after certain time of inactivity
To configure <code>logind</code> service to terminate inactive user sessions after <xccdf-1.2:sub idref="xccdf_org.ssgproject.content_value_var_logind_session_timeout" use="legacy"></xccdf-1.2:sub>...Rule Medium Severity -
Require Authentication for Emergency Systemd Target
Emergency mode is intended as a system recovery method, providing a single user root access to the system during a failed boot sequence. <br> <br> By default, Emergency mode is protected by...Rule Medium Severity -
Require Authentication for Single User Mode
Single-user mode is intended as a system recovery method, providing a single user root access to the system by providing a boot option at startup. <br> <br> By default, single-user mode is ...Rule Medium Severity -
Configure Screen Locking
When a user must temporarily leave an account logged-in, screen locking should be employed to prevent passersby from abusing the account. User education and training is particularly important for s...Group -
Configure Console Screen Locking
A console screen locking mechanism is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of th...Group -
Support session locking with tmux
Thetmux
terminal multiplexer is used to implement automatic session locking. It should be started from/etc/bashrc
or drop-in files within/etc/profile.d/
.Rule Medium Severity -
Support session locking with tmux (not enforcing)
Thetmux
terminal multiplexer is used to implement automatic session locking. It should be started from/etc/bashrc
or drop-in files within/etc/profile.d/
.Rule Medium Severity -
Configure the tmux lock session key binding
To set a key binding for the screen locking in <code>tmux</code> terminal multiplexer, the <code>session-lock</code> command must be bound to a key. Add the following line to <code>/etc/tmux.conf</...Rule Low Severity -
Prevent user from disabling the screen lock
Thetmux
terminal multiplexer is used to implement automatic session locking. It should not be listed in/etc/shells
.Rule Low Severity -
Hardware Tokens for Authentication
The use of hardware tokens such as smart cards for system login provides stronger, two-factor authentication than using a username and password. In Red Hat Enterprise Linux servers and workstation...Group
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