03.13.15: Communications Authenticity

Beyond CMMC Level 1

The free web app covers the 17 CMMC Level 1 practices. This requirement is part of the full NIST 800-171 set — get the desktop app to work on all 110 requirements with SPRS scoring. Previously saved data is shown read-only below, and your data always remains exportable in full.

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Security Requirements for 03.13.15 Communications Authenticity

Authenticity protection includes protecting against man-in-the-middle attacks, session hijacking, and the insertion of false information into communications sessions. This requirement addresses communications protection at the session versus packet level (e.g., sessions in service-oriented architectures providing web-based services) and establishes grounds for confidence at both ends of communications sessions in ongoing identities of other parties and in the validity of information transmitted.[SP 800-77], [SP 800-95], and [SP 800-113] provide guidance on secure communications sessions.

Assessment GuidanceExamine 0/7

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

Discussion

The intent of this requirement is to ensure a trust relationship is established between both ends of a communication session. Each end can be assured that the other end is who it is supposed to be. This is often implemented using a mutual authentication handshake when the session is established, especially between devices. Session authenticity is usually

provided by a security protocol enforced for a communication session. Choosing and enforcing a protocol will provide authenticity throughout a communications session.

Examples

Example 1
You are a system administrator responsible for ensuring that the two-factor user authentication mechanism for the servers is configured correctly. You purchase and maintain the digital certificate and replace it with a new one before the old one expires. You ensure the TLS configuration settings on the web servers, VPN solution, and other components that use TLS are correct, using secure settings that address risks against attacks on the encrypted sessions [a].

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.

System and communications protection policy
Procedures addressing session authenticity
System security plan
System design documentation
System configuration settings and associated documentation
System audit logs and records
Other relevant documents or records

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.

System or network administrators
Personnel with information security responsibilities

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 session authenticity

Potential Assessment Considerations

Is a communications protocol used that ensures the sending and receiving parties do not change during a communications session [a]?
Are controls in place to validate the identities and information transmitted to protect against man-in-the-middle attacks, session hijacking, and insertion of false information into communications sessions [a]?

Key References

NIST SP 800-171 Rev. 2 3.13.15

Overview