Vulnerability Discussion

By limiting the number of failed logon attempts the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account.

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

Check

Verify RHEL 9 is configured to lock an account until released by an administrator after three unsuccessful logon attempts with the command:

$ grep 'unlock_time =' /etc/security/faillock.conf

unlock_time = 0

If the "unlock_time" option is not set to "0", the line is missing, or commented out, this is a finding.

Fix

Configure RHEL 9 to lock an account until released by an administrator after three unsuccessful logon attempts with the command:

$ authselect enable-feature with-faillock

Then edit the "/etc/security/faillock.conf" file as follows:

unlock_time = 0