Profile Applicability:
 • Level 1

Description:
 Configuring limits on the number of same consecutive characters in passwords prevents users from choosing passwords with easily guessable patterns such as repeated characters, thereby strengthening password security.

Rationale:
 Restricting consecutive identical characters reduces the risk of weak passwords and enhances protection against guessing and brute-force attacks.

Impact:
 Pros:

  • Encourages stronger password choices.

  • Mitigates simple password patterns that are vulnerable to attacks.

Cons:

  • May add complexity for users creating passwords.

Default Value:
 This setting is not always configured by default and must be explicitly enabled.

Pre-requisites:

  • Root or sudo privileges to configure PAM modules such as pam_pwquality.

Remediation:

Test Plan:

Using Linux command line:

  1. Check /etc/security/pwquality.conf for maxrepeat parameter which controls max allowed consecutive identical characters:
    grep maxrepeat /etc/security/pwquality.conf

  2. Verify maxrepeat is set appropriately (e.g., 3 or fewer).

Implementation Plan:

Using Linux command line:

  1. Edit /etc/security/pwquality.conf to set maxrepeat, for example:
    maxrepeat = 3


  2. Save the file and ensure PAM uses pam_pwquality.

Backout Plan:

Using Linux command line:

  1. Remove or adjust the maxrepeat parameter if needed.

  2. Test password change functionality.

References: