RHEL 9 must automatically lock an account when three unsuccessful logon attempts occur during a 15-minute time period.

Documentable No

Rule ID SV-258056r1045143_rule

CCI References

CCI-000044CCI-002238

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 Procedure

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.

Fix Action

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