SI-11 Error Handling
High-Level Description
Family: System and Information Integrity (SI) Framework: NIST SP 800-53 Rev 5
Organizations consider the structure and content of error messages. The extent to which systems can handle error conditions is guided and informed by organizational policy and operational requirements. Exploitable information includes stack traces and implementation details; erroneous logon attempts with passwords mistakenly entered as the username; mission or business information that can be derived from, if not stated explicitly by, the information recorded; and personally identifiable information, such as account numbers, social security numbers, and credit card numbers. Error messages may also provide a covert channel for transmitting information.
What to Check
- Verify SI-11 Error Handling is documented in SSP
- Validate all 2 control requirements are implemented
- Confirm control is operating effectively
- Review evidence of continuous monitoring for SI-11
How to Test
Step 1: Review Documentation
Examine the System Security Plan (SSP) and related artifacts for SI-11 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 integrity monitoring | cloud_audit_monitoring |
| AWS CLI | Review GuardDuty/Inspector | aws guardduty list-detectors |
Remediation Guide
Control Statement
Generate error messages that provide information necessary for corrective actions without revealing information that could be exploited; and Reveal error messages only to [organization-defined].
Implementation Guidance
Organizations consider the structure and content of error messages. The extent to which systems can handle error conditions is guided and informed by organizational policy and operational requirements. Exploitable information includes stack traces and implementation details; erroneous logon attempts with passwords mistakenly entered as the username; mission or business information that can be derived from, if not stated explicitly by, the information recorded; and personally identifiable information, such as account numbers, social security numbers, and credit card numbers. Error messages may also provide a covert channel for transmitting information.
Risk Assessment
| Finding | Severity | Impact |
|---|---|---|
| SI-11 Error Handling not implemented | High | System and Information Integrity |
| SI-11 partially implemented | Medium | Incomplete System and Information Integrity |
CWE Categories
| CWE ID | Title |
|---|---|
| CWE-20 | Improper Input Validation |
References
- NIST SP 800-53 Rev 5 - SI-11
- 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 (AU-2, AU-3, SC-31, SI-2, SI-15) reviewed