The system must disable accounts after excessive login failures within a 15-minute interval.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-38501	RHEL-06-000357	SV-50302r1_rule		Medium

Description
Locking out user accounts after a number of incorrect attempts within a specific period of time prevents direct password guessing attacks.

STIG	Date
Red Hat Enterprise Linux 6 Security Technical Implementation Guide	2013-06-03

Details

Check Text ( C-46058r1_chk )
To ensure the failed password attempt policy is configured correctly, run the following command: # grep pam_faillock /etc/pam.d/system-auth-ac The output should show "fail_interval=" where "interval-in-seconds" is 900 (15 minutes) or greater. If the "fail_interval" parameter is not set, the default setting of 900 seconds is acceptable. If that is not the case, this is a finding.

Fix Text (F-43448r1_fix)
To configure the system to lock out accounts after a number of incorrect login attempts within a 15-minute interval using "pam_faillock.so": Add the following lines immediately below the "pam_env.so" statement in the AUTH section of "/etc/pam.d/system-auth-ac": auth [default=die] pam_faillock.so authfail deny=3 unlock_time=604800 fail_interval=900 auth required pam_faillock.so authsucc deny=3 unlock_time=604800 fail_interval=900 Note that any updates made to "/etc/pam.d/system-auth-ac" will be overwritten by the "authconfig" program. The "authconfig" program should not be used.

Fix Text (F-43448r1_fix)

To configure the system to lock out accounts after a number of incorrect login attempts within a 15-minute interval using "pam_faillock.so":

Add the following lines immediately below the "pam_env.so" statement in the AUTH section of
"/etc/pam.d/system-auth-ac":

auth [default=die] pam_faillock.so authfail deny=3 unlock_time=604800 fail_interval=900

auth required pam_faillock.so authsucc deny=3 unlock_time=604800 fail_interval=900

Note that any updates made to "/etc/pam.d/system-auth-ac" will be overwritten by the "authconfig" program. The "authconfig" program should not be used.