RHEL 8 must ensure account lockouts persist.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-230339	RHEL-08-020017	SV-230339r627750_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	2021-03-04

Details

Check Text ( C-33008r619903_chk )
Check that the faillock directory contents persist after a reboot with the following commands: 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 pam_faillock.so module is present in the "/etc/pam.d/system-auth" and " /etc/pam.d/password-auth" files: $ sudo grep pam_faillock.so /etc/pam.d/system-auth /etc/pam.d/password-auth /etc/pam.d/system-auth:auth required pam_faillock.so preauth /etc/pam.d/system-auth:auth required pam_faillock.so authfail /etc/pam.d/system-auth:account required pam_faillock.so /etc/pam.d/password-auth:auth required pam_faillock.so preauth /etc/pam.d/password-auth:auth required pam_faillock.so authfail /etc/pam.d/password-auth:account required pam_faillock.so preauth If the pam_failllock.so module is not present in the "/etc/pam.d/system-auth" and " /etc/pam.d/password-auth" files, this is a finding. Verify the "/etc/security/faillock.conf" file is configured use a non-default faillock directory to ensure contents persist after reboot: $ sudo grep 'dir =' /etc/security/faillock.conf dir = /var/log/faillock If the "dir" option is not set to a non-default documented tally log directory, is missing or commented out, this is a finding.

Check Text ( C-33008r619903_chk )

Check that the faillock directory contents persist after a reboot with the following commands:

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 pam_faillock.so module is present in the "/etc/pam.d/system-auth" and " /etc/pam.d/password-auth" files:

$ sudo grep pam_faillock.so /etc/pam.d/system-auth /etc/pam.d/password-auth

/etc/pam.d/system-auth:auth required pam_faillock.so preauth
/etc/pam.d/system-auth:auth required pam_faillock.so authfail
/etc/pam.d/system-auth:account required pam_faillock.so
/etc/pam.d/password-auth:auth required pam_faillock.so preauth
/etc/pam.d/password-auth:auth required pam_faillock.so authfail
/etc/pam.d/password-auth:account required pam_faillock.so preauth

If the pam_failllock.so module is not present in the "/etc/pam.d/system-auth" and " /etc/pam.d/password-auth" files, this is a finding.

Verify the "/etc/security/faillock.conf" file is configured use a non-default faillock directory to ensure contents persist after reboot:

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

dir = /var/log/faillock

If the "dir" option is not set to a non-default documented tally log directory, is missing or commented out, this is a finding.

Fix Text (F-32983r567764_fix)
Configure the operating system maintain the contents of the faillock directory after a reboot. 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 auth required pam_faillock.so authfail account required pam_faillock.so Add/Modify the "/etc/security/faillock.conf" file to match the following line: dir = /var/log/faillock

Fix Text (F-32983r567764_fix)

Configure the operating system maintain the contents of the faillock directory after a reboot.

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
auth required pam_faillock.so authfail
account required pam_faillock.so

Add/Modify the "/etc/security/faillock.conf" file to match the following line:

dir = /var/log/faillock