detecting-suspicious-assert
Detects suspicious use of assertions for security checks that can be disabled in production builds. Use when analyzing assertion usage, security checks, or investigating assert-related vulnerabilities.
When & Why to Use This Skill
This Claude skill automates the detection of security vulnerabilities arising from the misuse of assertions in production code. It specifically identifies instances where critical security checks—such as authentication, authorization, or input validation—are implemented using assertion macros that are typically disabled in release builds, helping developers prevent accidental security bypasses and logic flaws.
Use Cases
- Security Auditing: Automatically scanning large codebases to identify 'assert' statements that handle security-critical logic which would be stripped out during production compilation.
- CI/CD Integration: Enhancing the code review process by flagging risky assertion patterns in pull requests before they are merged into the main branch.
- Vulnerability Research: Assisting security researchers in locating exploitable bypasses in software where developers mistakenly relied on debug-only checks for resource allocation or bounds checking.
- Legacy Code Refactoring: Identifying and documenting technical debt where assertions were used as a shortcut for proper error handling and exception management.
| name | detecting-suspicious-assert |
|---|---|
| description | Detects suspicious use of assertions for security checks that can be disabled in production builds. Use when analyzing assertion usage, security checks, or investigating assert-related vulnerabilities. |
Suspicious Assert Detection
Detection Workflow
- Identify assert operations: Find all assert() calls, locate assertion macros, identify static_assert usage, map assertion patterns
- Analyze assert purpose: Determine assert intent, check if used for security, assess criticality of check, review assert context
- Check for bypass potential: Verify if asserts are disabled, assess release build behavior, check for compile-time flags, review build configuration
- Assess security impact: Can assert be bypassed? What's the security impact? Is critical check disabled? What's the exploit potential?
Key Patterns
- Asserts for security checks: using assert() for input validation, using assert() for security checks, using assert() for authentication, using assert() for authorization
- Asserts that can be disabled: critical checks using assert(), security-critical validations using assert(), resource allocation checks using assert(), bounds checks using assert()
- Asserts with side effects: asserts with function calls, asserts with assignments, asserts modifying state, asserts with non-pure expressions
- Incorrect assert usage: asserts on user-controlled data, asserts that can be bypassed, asserts in release builds, asserts in production code
Output Format
Report with: id, type, subtype, severity, confidence, location, vulnerability, assert_statement, assert_type, check_purpose, disabled_in_release, exploitable, attack_scenario, impact, mitigation.
Severity Guidelines
- HIGH: Assert used for critical security checks
- MEDIUM: Assert used for important validation
- LOW: Assert used for debugging only
See Also
patterns.md- Detailed detection patterns and exploitation scenariosexamples.md- Example analysis cases and code samplesreferences.md- CWE references and mitigation strategies