SC-23_session-authenticity

DevOps & Security

Protect the authenticity of communications sessions.

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Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/NIST/SP800-53_rev5/SC_system-and-communications-protection/SC-23_session-authenticity/SKILL.md

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SC-23 Session Authenticity

High-Level Description

Family: System and Communications Protection (SC) Framework: NIST SP 800-53 Rev 5

Protecting session authenticity addresses communications protection at the session level, not at the packet level. Such protection establishes grounds for confidence at both ends of communications sessions in the ongoing identities of other parties and the validity of transmitted information. Authenticity protection includes protecting against "man-in-the-middle" attacks, session hijacking, and the insertion of false information into sessions.

What to Check

Verify SC-23 Session Authenticity is documented in SSP
Confirm control is operating effectively
Review evidence of continuous monitoring for SC-23

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SC-23 implementation details. Verify the organization has documented how this control is satisfied.

Step 2: Validate Implementation

# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null

Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

Tools

Tool	Purpose	Usage
cloud-audit-mcp	Check encryption and network controls	`cloud_audit_encryption`
nmap	Network scanning	`nmap -sV --script ssl-enum-ciphers`

Remediation Guide

Control Statement

Protect the authenticity of communications sessions.

Implementation Guidance

Risk Assessment

Finding	Severity	Impact
SC-23 Session Authenticity not implemented	High	System and Communications Protection
SC-23 partially implemented	Medium	Incomplete System and Communications Protection

CWE Categories

CWE ID	Title
CWE-311	Missing Encryption of Sensitive Data

References

Checklist

Control documented in SSP
Implementation evidence collected
Operating effectiveness validated
Continuous monitoring in place
Related controls (AU-10, SC-8, SC-10, SC-11) reviewed