4.4.3 Ensure password reuse is limited

Information

The /etc/security/opasswd file stores the users' old passwords and can be checked to ensure that users are not recycling recent passwords.

Forcing users not to reuse their past 5 passwords make it less likely that an attacker will be able to guess the password.

Solution

NOTE: Pay special attention to the configuration. Incorrect configuration can cause system lock outs or unexpected behavior. This is example configuration. You configuration may differ based on previous changes to the files.

Edit the /etc/pam.d/common-password file to include:

- password required pam_pwhistory.so remember=5
- use_authtok on the pam_unix.so line

Example:

password required pam_pwhistory.so remember=5
password [success=1 default=ignore] pam_unix.so obscure sha512 use_authtok

See Also

https://workbench.cisecurity.org/benchmarks/13007

Item Details

Category: IDENTIFICATION AND AUTHENTICATION

References: 800-53|IA-5(1), CSCv7|4.4

Plugin: Unix

Control ID: 2c667aae10039ff89495a85f9894a8ccae0e3ad0d6c8306291a1a14e8e918135