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 locks an account after three unsuccessful logon attempts within a period of 15 minutes with the following command:

Note: If the system administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is Not Applicable.

$ grep fail_interval /etc/security/faillock.conf

fail_interval = 900

If the "fail_interval" option is not set to "900" or less (but not "0"), the line is commented out, or the line is missing, this is a finding.

Fix

To configure RHEL 9 to lock out the "root" account after a number of incorrect login attempts within 15 minutes using "pam_faillock.so", enable the feature using the following command:

$ authselect enable-feature with-faillock

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

fail_interval = 900