Title

The system must require passwords to contain at least one numeric character. (Cat III impact)

Discussion

Requiring digits makes password guessing attacks more difficult by ensuring a larger search space.

Check Content

To check how many digits are required in a password, run the following command: $ grep pam_cracklib /etc/pam.d/system-auth /etc/pam.d/password-auth Note: The "dcredit" parameter (as a negative number) will indicate how many digits are required. The DoD requires at least one digit in a password. This would appear as "dcredit=-1". If “dcredit” is not found or not set to the required value, this is a finding.

Fix Text

The pam_cracklib module's "dcredit" parameter controls requirements for usage of digits in a password. When set to a negative number, any password will be required to contain that many digits. When set to a positive number, pam_cracklib will grant +1 additional length credit for each digit. Edit /etc/pam.d/system-auth and /etc/pam.d/password-auth adding "dcredit=-1" after pam_cracklib.so to require use of a digit in passwords.

Additional Identifiers

Rule ID: SV-217892r603264_rule

Vulnerability ID: V-217892

Group Title: SRG-OS-000071

Expert Comments

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