Title

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

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 /etc/pam.d/password-auth Note: 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. Edit /etc/pam.d/system-auth and /etc/pam.d/password-auth adding "ucredit=-1" after pam_cracklib.so to require use of an uppercase character in passwords.

Additional Identifiers

Rule ID: SV-217893r603264_rule

Vulnerability ID: V-217893

Group Title: SRG-OS-000069

Expert Comments

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