RHEL 9 must automatically lock an account 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. Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005

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. Verify RHEL 9 locks an account after three unsuccessful logon attempts within a period of 15 minutes with the following command: $ sudo 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.

To configure RHEL 9 to lock out the "root" account after a number of incorrect logon attempts within 15 minutes using "pam_faillock.so", enable the feature using the following command: $ sudo authselect enable-feature with-faillock Then edit the "/etc/security/faillock.conf" file as follows: fail_interval = 900