Overview
  1. 03.01: Access Control
  2. 03.02: Awareness and Training
  3. 03.03: Audit and Accountability
  4. 03.04: Configuration Management
  5. 03.05: Identification and Authentication
  6. 03.06: Incident Response
  7. 03.07: Maintenance
  8. 03.08: Media Protection
  9. 03.09: Personnel Security
  10. 03.10: Physical Protection
  11. 03.11: Risk Assessment
  12. 03.12: Security Assessment
  13. 03.13: System and Communications Protection
  14. 03.14: System and Information Integrity

Security Requirements for 03.05.04 Replay-Resistant Authentication

Authentication processes resist replay attacks if it is impractical to successfully authenticate by recording or replaying previous authentication messages. Replay-resistant techniques include protocols that use nonces or challenges such as time synchronous or challenge-response one-time authenticators.[SP 800-63-3] provides guidance on digital identities.

Assessment GuidanceExamine 0/8

How an assessor determines this requirement is met. Source: CMMC Assessment Guide – Level 2, Version 2.13 (NIST SP 800-171 Rev. 2).

Discussion

When insecure protocols are used for access to computing resources, an adversary may be able to capture login information and immediately reuse (replay) it for other purposes. It is important to use mechanisms that resist this technique.

Example To protect your IT infrastructure, you understand that the methods for authentication must not be easily copied and re-sent to your systems by an adversary. You select Kerberos for authentication because of its built-in resistance to replay attacks. As a next step you upgrade all of your web applications to require Transport Layer Security (TLS), which also is replayresistant. Your use of MFA to protect remote access also confers some replay resistance.

Assessment Methods

Examine
The process of reviewing, inspecting, observing, studying, or analyzing assessment objects (e.g., policies, procedures, plans, system designs, mechanisms) to facilitate understanding, achieve clarification, or obtain evidence.Example: An assessor reads the access control policy and inspects system configuration settings to confirm they match.

Not all of the evidence listed is required to meet this requirement — check the items your organization has collected.

Interview
The process of holding discussions with individuals or groups within an organization to facilitate understanding, achieve clarification, or identify the location of evidence.Example: An assessor asks a system administrator to describe how user accounts are approved, reviewed, and disabled.
  • Personnel with system operations responsibilities
  • Personnel with account management responsibilities
  • Personnel with information security responsibilities
  • System or network administrators
  • System developers
Test
The process of exercising assessment objects (e.g., activities, mechanisms) under specified conditions to compare actual behavior with expected behavior.Example: An assessor attempts to sign in with a disabled account to confirm that access is denied.
  • Mechanisms supporting or implementing identification and authentication capability or replay resistant authentication mechanisms

Potential Assessment Considerations

  • Are only anti-replay authentication mechanisms used [a]?

Key References

NIST SP 800-171 Rev. 2 3.5.4

Evidence

  1. 03.05.04.a

    Replay-resistant authentication mechanisms are implemented for network account access to privileged and non-privileged accounts