If three unsuccessful root logon attempts within 15 minutes occur the associated account must be locked.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-71945	RHEL-07-010330	SV-86569r2_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	2017-12-14

Details

Check Text ( C-72177r2_chk )
Verify the operating system automatically locks the root account until it is released by an administrator when three unsuccessful logon attempts in 15 minutes are made. # grep pam_faillock.so /etc/pam.d/password-auth-ac auth required pam_faillock.so preauth silent audit deny=3 even_deny_root unlock_time=604800 fail_interval=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root unlock_time=604800 fail_interval=900 account required pam_faillock.so If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module name, this is a finding. # grep pam_faillock.so /etc/pam.d/system-auth-ac auth required pam_faillock.so preauth silent audit deny=3 even_deny_root unlock_time=604800 fail_interval=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root unlock_time=604800 fail_interval=900 account required pam_faillock.so If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module name, this is a finding.

Check Text ( C-72177r2_chk )

Verify the operating system automatically locks the root account until it is released by an administrator when three unsuccessful logon attempts in 15 minutes are made.

# grep pam_faillock.so /etc/pam.d/password-auth-ac
auth required pam_faillock.so preauth silent audit deny=3 even_deny_root unlock_time=604800 fail_interval=900
auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root unlock_time=604800 fail_interval=900
account required pam_faillock.so

If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module name, this is a finding.

# grep pam_faillock.so /etc/pam.d/system-auth-ac
auth required pam_faillock.so preauth silent audit deny=3 even_deny_root unlock_time=604800 fail_interval=900
auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root unlock_time=604800 fail_interval=900
account required pam_faillock.so

If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module name, this is a finding.

Fix Text (F-78297r2_fix)
Configure the operating system to automatically lock the root account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes are made. Modify the first three lines of the auth section of the "/etc/pam.d/system-auth-ac" and "/etc/pam.d/password-auth-ac" files to match the following lines: auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=604800 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=604800 account required pam_faillock.so Note: Any updates made to "/etc/pam.d/system-auth-ac" and "/etc/pam.d/password-auth-ac" may be overwritten by the "authconfig" program. The "authconfig" program should not be used.

Fix Text (F-78297r2_fix)

Configure the operating system to automatically lock the root account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes are made.

Modify the first three lines of the auth section of the "/etc/pam.d/system-auth-ac" and "/etc/pam.d/password-auth-ac" files to match the following lines:

auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=604800
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=604800
account required pam_faillock.so

Note: Any updates made to "/etc/pam.d/system-auth-ac" and "/etc/pam.d/password-auth-ac" may be overwritten by the "authconfig" program. The "authconfig" program should not be used.