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.

Check

Verify Amazon Linux 2023 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 Amazon Linux 2023 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