The system must prohibit the reuse of passwords within five iterations.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-50855	OL6-00-000274	SV-65061r5_rule		Medium

Description
Preventing reuse of previous passwords helps ensure that a compromised password is not reused by a user.

STIG	Date
Oracle Linux 6 Security Technical Implementation Guide	2019-03-20

Details

Check Text ( C-53327r6_chk )
To verify the password reuse setting is compliant, run the following command: # grep remember /etc/pam.d/system-auth /etc/pam.d/password-auth The output must be a line beginning with "password required pam_pwhistory.so" and ending with "remember=5". If the line is commented out, the line does not contain the specified elements, or the value for "remember" is less than “5”, this is a finding.

Check Text ( C-53327r6_chk )

To verify the password reuse setting is compliant, run the following command:

# grep remember /etc/pam.d/system-auth /etc/pam.d/password-auth

The output must be a line beginning with "password required pam_pwhistory.so" and ending with "remember=5".

If the line is commented out, the line does not contain the specified elements, or the value for "remember" is less than “5”, this is a finding.

Fix Text (F-55649r6_fix)
Do not allow users to reuse recent passwords. This can be accomplished by using the "remember" option for the "pam_pwhistory" PAM module. In the file "/etc/pam.d/system-auth", append "remember=5" to the line which refers to the "pam_pwhistory.so" module, as shown: password required pam_pwhistory.so [existing_options] remember=5 The DoD requirement is five passwords.