cyberstrikeus AC-9(2) Successful and Unsuccessful Logons
Enhancement of: AC-9
High-Level Description
Family: Access Control (AC) Framework: NIST SP 800-53 Rev 5
Information about the number of successful and unsuccessful logon attempts within a specified time period allows the user to recognize if the number and type of logon attempts are consistent with the user’s actual logon attempts.
What to Check
- Verify AC-9(2) Successful and Unsuccessful Logons is documented in SSP
- Confirm control is operating effectively
- Review evidence of continuous monitoring for AC-9(2)
- Verify enhancement builds upon base control AC-9
How to Test
Step 1: Review Documentation
Examine the System Security Plan (SSP) and related artifacts for AC-9(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
Notify the user, upon successful logon, of the number of [organization-defined] during [organization-defined].
Implementation Guidance
Information about the number of successful and unsuccessful logon attempts within a specified time period allows the user to recognize if the number and type of logon attempts are consistent with the user’s actual logon attempts.
Risk Assessment
| Finding | Severity | Impact |
|---|---|---|
| AC-9(2) Successful and Unsuccessful Logons not implemented | High | Access Control |
| AC-9(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-9(2)
- NIST SP 800-53A Rev 5 (Assessment Procedures)
- NIST SP 800-53 Rev 5 Full Catalog
Checklist
- Control documented in SSP
- Implementation evidence collected
- Operating effectiveness validated
- Continuous monitoring in place
- Related controls (none) reviewed