5.3.1 Ensure password creation requirements are configured

Information

The pam_cracklib.so module checks the strength of passwords. It performs checks including ensuring a password is not a dictionary word, it is a certain length, contains a mix of characters (e.g. alphabet, numeric, other) and more.

The following are definitions of the pam_cracklib.so options:

- retry=3 - Allow 3 tries before sending back a failure.
- minlen=14 - password must be 14 characters or more
- dcredit=-1 - provide at least one digit
- ucredit=-1 - provide at least one uppercase character
- ocredit=-1 - provide at least one special character
- lcredit=-1 - provide at least one lowercase character

Additional module options may be set. This recommendation only covers:

- minlen=
- dcredit=
- ucredit=
- ocredit=
- lcredit=

Note: The settings shown above are one possible policy. If local site policy requires stricter settings, alter these values to conform to your organization's password policies.

Strong passwords and limited attempts before locking an account protect systems from being hacked through brute force methods.

Solution

Run the following command:

# pam-config -a --cracklib-minlen=14 --cracklib-retry=3 --cracklib-lcredit=-1 --cracklib-ucredit=-1 --cracklib-dcredit=-1 --cracklib-ocredit=-1 --cracklib

- OR -

Edit the /etc/pam.d/common-password file to include the appropriate options for pam_cracklib.so and to conform to site policy:

password requisite pam_cracklib.so retry=3 minlen=14 dcredit=-1 ucredit=-1 ocredit=-1 lcredit=-1

See Also

https://workbench.cisecurity.org/benchmarks/22179

Item Details

Category: IDENTIFICATION AND AUTHENTICATION

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

Plugin: Unix

Control ID: 26cdae808eccf7d9fe641a44109f65946890a1c301f24889cf493097f56e57af