Amazon Linux 2023 must automatically lock the root account until the root 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-forcing, is reduced. Limits are imposed by locking the account.
Check
Verify Amazon Linux 2023 is configured to lock the root account after three unsuccessful logon attempts with the command:
If the "even_deny_root" option is not set, is missing or commented out, this is a finding.
Fix
Configure Amazon Linux 2023 to lock out the "root" account after a number of incorrect login attempts using "pam_faillock.so", first enable the feature using the following command:
$ sudo authselect enable-feature with-faillock
Then edit the "/etc/security/faillock.conf" file as follows:
add or uncomment the following line: even_deny_root