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.

Check

Verify AlmaLinux OS 9 is configured to lock the root account after three unsuccessful logon attempts with the command:

$ grep even_deny_root /etc/security/faillock.conf

even_deny_root

If the "even_deny_root" option is not set, is missing, or is commented out, this is a finding.

Fix

Configure AlmaLinux OS 9 to lock the root account after a number of incorrect login attempts using pam_faillock.

First, enable the feature using the following command:

$ authselect enable-feature with-faillock

Then, add or uncomment the following line in the "/etc/security/faillock.conf" file:

even_deny_root