AlmaLinux OS 9 must configure the use of the pam_faillock.so module in the /etc/pam.d/system-auth file.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-269150	SRG-OS-000021-GPOS-00005	ALMA-09-007830	SV-269150r1050032_rule	2025-02-20	1

Description
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. If the pam_faillock.so module is not loaded, the system will not correctly lockout accounts to prevent password guessing attacks.

ℹ️ Check
Verify the pam_faillock.so module is present in the "/etc/pam.d/system-auth" file: $ grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so If the pam_faillock.so module is not present in the "/etc/pam.d/system-auth" file with the "preauth" line listed before pam_unix.so, this is a finding. If the system administrator (SA) can demonstrate that the required configuration is contained in a PAM configuration file included or substacked from the system-auth file, this is not a finding.

ℹ️ Check

Verify the pam_faillock.so module is present in the "/etc/pam.d/system-auth" file: $ grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so If the pam_faillock.so module is not present in the "/etc/pam.d/system-auth" file with the "preauth" line listed before pam_unix.so, this is a finding. If the system administrator (SA) can demonstrate that the required configuration is contained in a PAM configuration file included or substacked from the system-auth file, this is not a finding.

✔️ Fix
Configure AlmaLinux OS 9 to include the use of the pam_faillock.so module in the /etc/pam.d/system-auth file. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" file to match the following lines, ensuring that the "preauth" line is listed before pam_unix.so. auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so Note: Do not simply copy these three lines into the file; their location/order is important.

✔️ Fix

Configure AlmaLinux OS 9 to include the use of the pam_faillock.so module in the /etc/pam.d/system-auth file. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" file to match the following lines, ensuring that the "preauth" line is listed before pam_unix.so. auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so Note: Do not simply copy these three lines into the file; their location/order is important.