RHEL-08-020022 - RHEL 8 must include root when automatically locking an account until the locked account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period.

Information

By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account.

RHEL 8 can utilize the 'pam_faillock.so' for this purpose. Note that manual changes to the listed files may be overwritten by the 'authselect' program.

From 'Pam_Faillock' man pages: Note that the default directory that 'pam_faillock' uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable a different tally directory must be set with the 'dir' option.

In RHEL 8.2 the '/etc/security/faillock.conf' file was incorporated to centralize the configuration of the pam_faillock.so module. Also introduced is a 'local_users_only' option that will only track failed user authentication attempts for local users in /etc/passwd and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout.

Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128

Solution

Configure the operating system to include root when locking an account after three unsuccessful logon attempts occur in 15 minutes.

Add/Modify the appropriate sections of the '/etc/pam.d/system-auth' and '/etc/pam.d/password-auth' files to match the following lines:

auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0
auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0
account required pam_faillock.so

The 'sssd' service must be restarted for the changes to take effect. To restart the 'sssd' service, run the following command:

$ sudo systemctl restart sssd.service

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_RHEL_8_V2R1_STIG.zip

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-7a., CAT|II, CCI|CCI-000044, Rule-ID|SV-230344r1017156_rule, STIG-ID|RHEL-08-020022, Vuln-ID|V-230344

Plugin: Unix

Control ID: fc56db26e3f18cb9ea49d8f3d8a15c09bb11a71c7e03424f4a80a1ddcedf6d2d