SI-11_error-handling

Development

Generate error messages that provide information necessary for corrective actions without revealing information that could be exploited;

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Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/NIST/SP800-53_rev5/SI_system-and-information-integrity/SI-11_error-handling/SKILL.md

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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

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

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