OL 8 systems below version 8.2 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-248654	OL08-00-020012	SV-248654r853777_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. OL 8 can use 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

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. OL 8 can use 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

STIG	Date
Oracle Linux 8 Security Technical Implementation Guide	2022-09-07

Details

Check Text ( C-52088r779526_chk )
Verify the system locks an account after three unsuccessful logon attempts within a period of 15 minutes with the following commands. 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. Note: This check applies to OL versions 8.0 and 8.1. If the system is OL version 8.2 or newer, this check is not applicable. $ sudo grep pam_faillock.so /etc/pam.d/password-auth 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 If the "fail_interval" option is not set to "900" or more on the "preauth" lines with the "pam_faillock.so" module or is missing from this line, this is a finding. $ sudo grep pam_faillock.so /etc/pam.d/system-auth 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 If the "fail_interval" option is not set to "900" or more on the "preauth" lines with the "pam_faillock.so" module or is missing from this line, this is a finding.

Check Text ( C-52088r779526_chk )

Verify the system locks an account after three unsuccessful logon attempts within a period of 15 minutes with the following commands.

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.

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

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

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

If the "fail_interval" option is not set to "900" or more on the "preauth" lines with the "pam_faillock.so" module or is missing from this line, this is a finding.

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

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

If the "fail_interval" option is not set to "900" or more on the "preauth" lines with the "pam_faillock.so" module or is missing from this line, this is a finding.

Fix Text (F-52042r779527_fix)
Configure the operating system to lock an account when 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

Fix Text (F-52042r779527_fix)

Configure the operating system to lock an account when 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