The system must require passwords to contain at least one uppercase alphabetic character.

From Red Hat Enterprise Linux 6 Security Technical Implementation Guide

Associated with: CCI-000192

SV-50370r1_rule The system must require passwords to contain at least one uppercase alphabetic character.

Vulnerability discussion

Requiring a minimum number of uppercase characters makes password guessing attacks more difficult by ensuring a larger search space.

Check content

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

Fix text

The pam_cracklib module's "ucredit=" parameter controls requirements for usage of uppercase letters in a password. When set to a negative number, any password will be required to contain that many uppercase characters. When set to a positive number, pam_cracklib will grant +1 additional length credit for each uppercase character. Add "ucredit=-1" after pam_cracklib.so to require use of an uppercase character in passwords.

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