Vulnerability Discussion
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.
Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005
Check
Verify RHEL 9 is configured to lock an account after three unsuccessful logon attempts with the command:
$ grep 'deny =' /etc/security/faillock.conf
deny = 3
If the "deny" option is not set to "3" or less (but not "0"), is missing or commented out, this is a finding.
Fix
Configure RHEL 9 to lock an account when three unsuccessful logon attempts occur.
Add/modify the "/etc/security/faillock.conf" file to match the following line:
deny = 3