Cis Ubuntu1204 V110 9 2 1

9.2.1 Set Password Creation Requirement Parameters Using pam_cracklib (Scored)

Profile Applicability

• Level 1

Description

The pam_cracklib module checks the strength of passwords. It performs checks such as making sure 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

The setting shown above is one possible policy. Alter these values to conform to your own organization's password policies.

Rationale

Strong passwords protect systems from being hacked through brute force methods.

Audit Procedure

Using Command Line

Perform the following to determine the current settings in the /etc/pam.d/common-password file:

grep pam_cracklib.so /etc/pam.d/common-password

Expected Result

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

Remediation

Using Command Line

Set the pam_cracklib.so parameters as follows in /etc/pam.d/common-password:

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

Default Value

No password creation requirements are set by default.

References

• CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

Profile

Level 1 - Scored