5.3.3.1.8 Ensure unlock_time is configured on the pam_faillock module

Information

The operating system must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period.

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.

RHEL 8 operating systems can utilize the "pam_faillock.so" for this purpose. Note that manual changes to the listed files may be overwritten by the "authselect" program.

From "Pam_Faillock" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable a different tally directory must be set with the "dir" option.

Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128

Solution

Configure the operating system to lock an account until released by an administrator when three unsuccessful logon attempts occur in 15 minutes.

Add/Modify the appropriate sections of the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files to match the following lines:

auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0
auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0
account required pam_faillock.so

The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command:

# systemctl restart sssd.service

See Also

https://workbench.cisecurity.org/benchmarks/19886