SC-23

SC-23 SESSION AUTHENTICITY

Overview

Number	Title	Impact	Priority	Subject Area
SC-23	Session Authenticity	MODERATE	P1	System And Communications Protection

Instructions
The information system protects the authenticity of communications sessions.

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.

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.

Enhancements

SC-23 (1) Invalidate Session Identifiers At Logout

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

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

SC-23 (2) User-Initiated Logouts / Message Displays

Withdrawn: Incorporated into AC-12 (1).

SC-23 (3) Unique Session Identifiers With Randomization

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.

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.

SC-23 (4) Unique Session Identifiers With Randomization

Withdrawn: Incorporated into SC-23 (3).

SC-23 (5) Allowed Certificate Authorities

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.

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