AC 12(2) Termination Message

---
name: "AC-12(2)_termination-message"
description: "Display an explicit logout message to users indicating the termination of authenticated communications sessions."
category: "authorization"
version: "5.2.0"
author: "cyberstrike-official"
tags:
  - nist
  - sp800-53
  - rev5
  - ac-12-2
  - ac
  - enhancement
tech_stack:
  - aws
  - azure
  - gcp
  - linux
  - windows
cwe_ids:
  - CWE-284
chains_with: []
prerequisites:
  - AC-12
severity_boost: {}
---

# AC-12(2) Termination Message

> **Enhancement of:** AC-12

## High-Level Description

**Family:** Access Control (AC)
**Framework:** NIST SP 800-53 Rev 5

Logout messages for web access can be displayed after authenticated sessions have been terminated. However, for certain types of sessions, including file transfer protocol (FTP) sessions, systems typically send logout messages as final messages prior to terminating sessions.

## What to Check

- [ ] Verify AC-12(2) Termination Message is documented in SSP
- [ ] Confirm control is operating effectively
- [ ] Review evidence of continuous monitoring for AC-12(2)
- [ ] Verify enhancement builds upon base control AC-12

## How to Test

### Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for AC-12(2) 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 IAM policies and access controls | `cloud_audit_iam_policies` |
| hackbrowser | Test web application access controls   | `hackbrowser`        |

## Remediation Guide

### Control Statement

Display an explicit logout message to users indicating the termination of authenticated communications sessions.

### Implementation Guidance

Logout messages for web access can be displayed after authenticated sessions have been terminated. However, for certain types of sessions, including file transfer protocol (FTP) sessions, systems typically send logout messages as final messages prior to terminating sessions.

## Risk Assessment

| Finding                                      | Severity | Impact                    |
| -------------------------------------------- | -------- | ------------------------- |
| AC-12(2) Termination Message not implemented | High     | Access Control            |
| AC-12(2) partially implemented               | Medium   | Incomplete Access Control |

## CWE Categories

| CWE ID  | Title                   |
| ------- | ----------------------- |
| CWE-284 | Improper Access Control |

## References

- [NIST SP 800-53 Rev 5 - AC-12(2)](https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=ac-12.2)
- [NIST SP 800-53A Rev 5 (Assessment Procedures)](https://csrc.nist.gov/pubs/sp/800/53/a/r5/final)
- [NIST SP 800-53 Rev 5 Full Catalog](https://csrc.nist.gov/pubs/sp/800/53/r5/upd1/final)

## Checklist

- [ ] Control documented in SSP
- [ ] Implementation evidence collected
- [ ] Operating effectiveness validated
- [ ] Continuous monitoring in place
- [ ] Related controls (none) reviewed