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  2. NIST SP 800-53R4
  3. SC-23

SC — SYSTEM AND COMMUNICATIONS PROTECTION

SC-23: SESSION AUTHENTICITY

  • NIST 800-53R4 Membership SC-23:
  • MODERATE
  • HIGH

The information system protects the authenticity of communications sessions.

SUPPLEMENTAL GUIDANCE

This control 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. Authenticity protection includes, for example, protecting against man-in-the-middle attacks/session hijacking and the insertion of false information into sessions.

CONTROL ENHANCEMENTS

SC-23 (1) SESSION AUTHENTICITY | INVALIDATE SESSION IDENTIFIERS AT LOGOUT

The information system invalidates session identifiers upon user logout or other session termination.

Supplemental Guidance:

This control enhancement curtails the ability of adversaries from capturing and continuing to employ previously valid session IDs.

SC-23 (2) SESSION AUTHENTICITY | USER-INITIATED LOGOUTS / MESSAGE DISPLAYS

[Withdrawn: Incorporated into AC-12 (1)].

SC-23 (3) SESSION AUTHENTICITY | UNIQUE SESSION IDENTIFIERS WITH RANDOMIZATION

The information system generates a unique session identifier for each session with [Assignment: organization-defined randomness requirements] and recognizes only session identifiers that are system-generated.

Supplemental Guidance:

This control enhancement curtails the ability of adversaries from reusing previously valid session IDs. Employing the concept of randomness in the generation of unique session identifiers helps to protect against brute-force attacks to determine future session identifiers.

RELATED CONTROLS: SC-23 (3)

SC-23 (4) SESSION AUTHENTICITY | UNIQUE SESSION IDENTIFIERS WITH RANDOMIZATION

[Withdrawn: Incorporated into SC-23 (3)].

SC-23 (5) SESSION AUTHENTICITY | ALLOWED CERTIFICATE AUTHORITIES

The information system only allows the use of [Assignment: organization-defined certificate authorities] for verification of the establishment of protected sessions.

Supplemental Guidance:

Reliance on certificate authorities (CAs) for the establishment of secure sessions includes, for example, the use of Secure Socket Layer (SSL) and/or Transport Layer Security (TLS) certificates. These certificates, after verification by the respective certificate authorities, facilitate the establishment of protected sessions between web clients and web servers.

RELATED CONTROLS: SC-23 (5)

REFERENCES:

  • NIST Special Publication 800-52
  • NIST Special Publication 800-77
  • NIST Special Publication 800-95