The Red Hat Enterprise Linux operating system must lock the associated account after three unsuccessful root logon attempts are made within a 15-minute period.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-204428	RHEL-07-010330	SV-204428r880845_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 forcing, is reduced. Limits are imposed by locking the account. Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005

STIG	Date
Red Hat Enterprise Linux 7 Security Technical Implementation Guide	2022-12-06

Details

Check Text ( C-4552r880843_chk )
Verify the operating system automatically locks the root account, for a minimum of 15 minutes, when three unsuccessful logon attempts in 15 minutes are made. # grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module, is commented out, or is missing from a line, this is a finding. # grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module, is commented out, or is missing from a line, this is a finding.

Check Text ( C-4552r880843_chk )

Verify the operating system automatically locks the root account, for a minimum of 15 minutes, when three unsuccessful logon attempts in 15 minutes are made.

# grep pam_faillock.so /etc/pam.d/password-auth

auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900
auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900
account required pam_faillock.so

If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module, is commented out, or is missing from a line, this is a finding.

# grep pam_faillock.so /etc/pam.d/system-auth

auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900
auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900
account required pam_faillock.so

If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module, is commented out, or is missing from a line, this is a finding.

Fix Text (F-4552r880844_fix)
Configure the operating system to automatically lock the root account, for a minimum of 15 minutes, when three unsuccessful logon attempts in 15 minutes are made. Modify the first three lines of the auth section and the first line of the account section 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 silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth sufficient pam_unix.so try_first_pass auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so Note: Per requirement RHEL-07-010199, RHEL 7 must be configured to not overwrite custom authentication configuration settings while using the authconfig utility, otherwise manual changes to the listed files will be overwritten whenever the authconfig utility is used.

Fix Text (F-4552r880844_fix)

Configure the operating system to automatically lock the root account, for a minimum of 15 minutes, when three unsuccessful logon attempts in 15 minutes are made.

Modify the first three lines of the auth section and the first line of the account section 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 silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900
auth sufficient pam_unix.so try_first_pass
auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900
account required pam_faillock.so

Note: Per requirement RHEL-07-010199, RHEL 7 must be configured to not overwrite custom authentication configuration settings while using the authconfig utility, otherwise manual changes to the listed files will be overwritten whenever the authconfig utility is used.