RHEL-08-020018 - RHEL 8 must prevent system messages from being presented when three unsuccessful logon attempts occur.

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.

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

Solution

Configure the operating system to prevent informative messages from being presented at logon attempts.

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-230340r1017152_rule, STIG-ID|RHEL-08-020018, Vuln-ID|V-230340

Plugin: Unix

Control ID: b52a2263505fad36ac68ec7b18680220aa8b517f20eb853eb7112f23b6887680