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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-50635	OL6-00-000357	SV-64841r2_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
Oracle Linux 6 Security Technical Implementation Guide	2015-03-23

Details

Check Text ( C-53141r2_chk )
To ensure the failed password attempt policy is configured correctly, run the following command: $ grep pam_faillock /etc/pam.d/system-auth /etc/pam.d/password-auth For each file, 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.

Check Text ( C-53141r2_chk )

To ensure the failed password attempt policy is configured correctly, run the following command:

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

For each file, 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-55431r2_fix)
Utilizing "pam_faillock.so", the "fail_interval" directive configures the system to lock out accounts after a number of incorrect logon attempts. Add the following "fail_interval" directives to "pam_faillock.so" immediately below the "pam_unix.so" statement in "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth": 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

Fix Text (F-55431r2_fix)

Utilizing "pam_faillock.so", the "fail_interval" directive configures the system to lock out accounts after a number of incorrect logon attempts.

Add the following "fail_interval" directives to "pam_faillock.so" immediately below the "pam_unix.so" statement in "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth":

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