ac-9-previous-logon-notification

name	AC-9_previous-logon-notification
description	Notify the user, upon successful logon to the system, of the date and time of the last logon.
category	authorization
version	5.2.0
author	cyberstrike-official
tags	["nist","sp800-53","rev5","ac-9","ac"]
tech_stack	["aws","azure","gcp","linux","windows"]
cwe_ids	["CWE-284"]
chains_with	["AC-7","PL-4"]
prerequisites	[]
severity_boost	{"AC-7":"Chain with AC-7 for comprehensive security coverage","PL-4":"Chain with PL-4 for comprehensive security coverage"}

AC-9 Previous Logon Notification

High-Level Description

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

Previous logon notification is applicable to system access via human user interfaces and access to systems that occurs in other types of architectures. Information about the last successful logon allows the user to recognize if the date and time provided is not consistent with the user’s last access.

What to Check

• Verify AC-9 Previous Logon Notification is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for AC-9

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for AC-9 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-mcp	Test web application access controls	browser_auth_test

Remediation Guide

Control Statement

Notify the user, upon successful logon to the system, of the date and time of the last logon.

Implementation Guidance

Previous logon notification is applicable to system access via human user interfaces and access to systems that occurs in other types of architectures. Information about the last successful logon allows the user to recognize if the date and time provided is not consistent with the user’s last access.

Risk Assessment

Finding	Severity	Impact