Guide to the Secure Configuration of Red Hat Enterprise Linux 9
Rules, Groups, and Values defined within the XCCDF Benchmark
-
Verify Group Ownership of Message of the Day Banner
To properly set the group owner of/etc/motd
, run the command:$ sudo chgrp root /etc/motd
Rule Medium Severity -
Verify ownership of System Login Banner
To properly set the owner of/etc/issue
, run the command:$ sudo chown root /etc/issue
Rule Medium Severity -
Verify ownership of Message of the Day Banner
To properly set the owner of/etc/motd
, run the command:$ sudo chown root /etc/motd
Rule Medium Severity -
Verify permissions on System Login Banner
To properly set the permissions of/etc/issue
, run the command:$ sudo chmod 0644 /etc/issue
Rule Medium Severity -
Verify permissions on System Login Banner for Remote Connections
To properly set the permissions of/etc/issue.net
, run the command:$ sudo chmod 0644 /etc/issue.net
Rule Medium Severity -
Verify permissions on Message of the Day Banner
To properly set the permissions of/etc/motd
, run the command:$ sudo chmod 0644 /etc/motd
Rule Medium Severity -
Implement a GUI Warning Banner
In the default graphical environment, users logging directly into the system are greeted with a login screen provided by the GNOME Display Manager (GDM). The warning banner should be displayed in t...Group -
Password Hashing algorithm
Specify the system default encryption algorithm for encrypting passwords. Defines the value set as ENCRYPT_METHOD in /etc/login.defs.Value -
remember
The last n passwords for each user are saved in <code>/etc/security/opasswd</code> in order to force password change history and keep the user from alternating between the same password too frequen...Value -
Install pam_pwquality Package
Thelibpwquality
package can be installed with the following command:$ sudo dnf install libpwquality
Rule Medium Severity -
Disallow Configuration to Bypass Password Requirements for Privilege Escalation
Verify the operating system is not configured to bypass password requirements for privilege escalation. Check the configuration of the "/etc/pam.d/sudo" file with the following command: <pre>$ sudo...Rule Medium Severity -
Set Lockouts for Failed Password Attempts
The <code>pam_faillock</code> PAM module provides the capability to lock out user accounts after a number of failed login attempts. Its documentation is available in <code>/usr/share/doc/pam-VERSIO...Group -
fail_deny
Number of failed login attempts before account lockoutValue -
faillock directory
The directory where the user files with the failure records are keptValue -
fail_interval
Interval for counting failed login attempts before account lockoutValue -
fail_unlock_time
Seconds before automatic unlocking or permanently locking after excessive failed loginsValue -
tally2_unlock_time
Seconds before automatic unlocking or permanently locking after excessive failed loginsValue -
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 syste...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 -
Set Password Quality Requirements with pam_pwquality
The <code>pam_pwquality</code> PAM module can be configured to meet requirements for a variety of policies. <br> <br> For example, to configure <code>pam_pwquality</code> to requi...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 -
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 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 - 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 Enforces Password Requirements - Minimum Length
The pam_pwquality module's <code>minlen</code> parameter controls requirements for minimum characters required in a password. Add <code>minlen=<xccdf-1.2:sub idref="xccdf_org.ssgproject.content_val...Rule Medium Severity -
Ensure PAM Enforces Password Requirements - Minimum Special Characters
The pam_pwquality module's <code>ocredit=</code> parameter controls requirements for usage of special (or "other") characters in a password. When set to a negative number, any password will be requ...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 -
Write Audit Logs to the Disk
To configure Audit daemon to write Audit logs to the disk, setwrite_logs
toyes
in/etc/audit/auditd.conf
. This is the default setting.Rule Medium Severity -
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 -
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 PAM''s Password Hashing Algorithm - password-auth
The PAM system service can be configured to only store encrypted representations of passwords. In <code>/etc/pam.d/password-auth</code>, the <code>password</code> section of the file controls which...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 configu...Rule High Severity
Node 2
The content of the drawer really is up to you. It could have form fields, definition lists, text lists, labels, charts, progress bars, etc. Spacing recommendation is 24px margins. You can put tabs in here, and can also make the drawer scrollable.