IA.L2-3.5.8: Password Reuse Assessment Guide

Official reference

The requirement

Prohibit password reuse for a specified number of generations.

DoD CMMC Assessment Guide, Level 2, version 2.13. IA.L2-3.5.8; requirement and objectives, printed page 128 ↗

Assessment objectives

What must be established

Determine if each applicable objective is satisfied. The labels below follow the cited DoD assessment guide.

[a]
the number of generations during which a password cannot be reused is specified and
[b]
reuse of passwords is prohibited during the specified number of generations.

MET requires evidence that all applicable objectives are satisfied. Final, approved evidence is needed. A NOT APPLICABLE determination needs a scope-based basis and is equivalent to MET for scoring. Enduring exceptions and temporary deficiencies have specific conditions under 32 CFR 170.24; they are not a general permission to defer implementation.

GAVII Cybersecurity assessment approach

Connect the objective to the evidence

Determine the required history depth and how it is implemented. Reset procedures and separate application credentials deserve review because they can bypass a central policy.

Assessment focus: objectives [a], [b]. Use the methods together; a single example does not establish every objective.

Examine

Inspect the specified history value, effective password-history settings, and reset procedures.

Interview

Can an administrative reset or an application-specific password change bypass the reuse restriction?

Demonstrate or test

Use a controlled account to demonstrate rejection of a recently used password within the specified history.

Evidence gaps to look for

The organization specifies a history depth but one password store retains less.
Help-desk resets undermine enforcement.

GAVII Cybersecurity’s examples illustrate ways to examine, interview, and test. They are not a mandatory artifact list or a guarantee of an assessment result. Combine methods and address every applicable objective in the actual scope.

Assessment constraints

Scoring and POA&M eligibility

Score: 1

If this requirement is NOT MET, deduct 1 point from the Level 2 maximum of 110. The deduction applies to the requirement, not separately to each objective.

Scoring rule ↗

POA&M: Eligible

Potentially eligible only if all Conditional Level 2 criteria are satisfied, including a score of at least 88 out of 110 and timely closeout. Eligibility is not a finding that this requirement is MET.

POA&M rule ↗

Conditional Level 2 requires a score of at least 88 out of 110 and satisfaction of every eligibility condition. A 1-point requirement is not automatically eligible. The permitted POA&M must be closed through the appropriate closeout assessment within 180 days of the Conditional CMMC Status Date. An operational remediation plan does not confer Conditional Status.

Assessment planning

Location and observation

Not specifically listed in CAP P.11

This requirement is not specifically listed in CAP P.11. That does not establish that remote assessment is sufficient: the Lead CCA and C3PAO determine an adequate approach for the actual scope and evidence.

CAP §P.11, pages 10–11 ↗

Check the source

References and related requirements

DoD CMMC Assessment Guide, Level 2 ↗IA.L2-3.5.8; requirement and objectives, printed page 128. 2.13, September 2024.
32 CFR 170.24: Assessment findings and scoring ↗170.24(b) and (c)(2). Current electronic Code of Federal Regulations.
32 CFR 170.21: POA&M eligibility and closeout ↗170.21(a)(2) and (b). Current electronic Code of Federal Regulations.
NIST SP 800-171 Rev. 2 ↗Requirement 3.5.8. February 2020, updated January 2021.
NIST SP 800-171A ↗Assessment procedure 3.5.8. June 2018.
Cyber AB CMMC Assessment Process (CAP) ↗P.11, printed pages 10-11; Level 2 certification assessment-location planning. 2.0, December 2024.

Program timing and contract applicability can change independently of these requirements. Check current DoD program notices and your solicitation or contract before making a compliance decision. Open the official DoD resource hub.

Password Reuse