RHEL 8 must automatically lock an account when three unsuccessful logon attempts occur during a 15-minute time period.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-230335	RHEL-08-020013	SV-230335r743969_rule		Medium

Description
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. 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. From "faillock.conf" 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

Description

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. 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. From "faillock.conf" 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

STIG	Date
Red Hat Enterprise Linux 8 Security Technical Implementation Guide	2021-12-03

Details

Check Text ( C-33004r743967_chk )
Note: This check applies to RHEL versions 8.2 or newer, if the system is RHEL version 8.0 or 8.1, this check is not applicable. Verify the "/etc/security/faillock.conf" file is configured to lock an account after three unsuccessful logon attempts within 15 minutes: $ sudo grep 'fail_interval =' /etc/security/faillock.conf fail_interval = 900 If the "fail_interval" option is not set to "900" or more, is missing or commented out, this is a finding.

Check Text ( C-33004r743967_chk )

Note: This check applies to RHEL versions 8.2 or newer, if the system is RHEL version 8.0 or 8.1, this check is not applicable.

Verify the "/etc/security/faillock.conf" file is configured to lock an account after three unsuccessful logon attempts within 15 minutes:

$ sudo grep 'fail_interval =' /etc/security/faillock.conf

fail_interval = 900

If the "fail_interval" option is not set to "900" or more, is missing or commented out, this is a finding.

Fix Text (F-32979r743968_fix)
Configure the operating system to lock an account when three unsuccessful logon attempts occur in 15 minutes. Add/Modify the "/etc/security/faillock.conf" file to match the following line: fail_interval = 900