detecting-use-after-free
Detects use-after-free vulnerabilities by identifying pointer dereferences after memory deallocation. Use when analyzing memory management, cleanup code, or investigating dangling pointer issues.
When & Why to Use This Skill
This Claude skill specializes in detecting use-after-free vulnerabilities by analyzing memory management patterns and identifying pointer dereferences after deallocation. It enhances software security by automating the identification of dangling pointers, double-free errors, and invalid memory access, providing detailed exploitability assessments and mitigation strategies to prevent memory corruption and code execution exploits.
Use Cases
- Security Vulnerability Assessment: Automatically scan source code to identify high-risk use-after-free vulnerabilities that could lead to remote code execution or data corruption.
- Memory Management Debugging: Trace pointer lifecycles and control flows to resolve complex dangling pointer issues and intermittent crashes in C/C++ applications.
- Secure Code Review: Enhance the peer review process by systematically checking for double-free errors and improper pointer handling during memory cleanup operations.
- Exploitability Analysis: Evaluate the severity of detected memory issues by determining if an attacker can control freed memory or trigger useful use-after-free conditions.
| name | detecting-use-after-free |
|---|---|
| description | Detects use-after-free vulnerabilities by identifying pointer dereferences after memory deallocation. Use when analyzing memory management, cleanup code, or investigating dangling pointer issues. |
Use-After-Free Detection
Detection Workflow
- Identify free operations: Find all free(), realloc(), delete calls and note the pointer being freed
- Trace pointer usage: Use
xrefs_toto find all dereferences of the pointer - Check control flow: Analyze paths through code to identify usage after free
- Assess exploitability: Can attacker control freed memory? Is there a useful use-after-free? Can memory be reallocated?
Key Patterns
- Pointer dereference after free()
- Double free vulnerabilities
- Invalid pointer access after realloc()
- Reference counting issues
Output Format
Report with: id, type, subtype, severity, confidence, location, freed pointer, free operation, use operation, use-after-free status, distance, exploitability, attack scenario, impact, mitigation.
Severity Guidelines
- CRITICAL: Use-after-free with code execution
- HIGH: Use-after-free with data corruption
- MEDIUM: Use-after-free causing crashes
- LOW: Use-after-free with limited impact
See Also
patterns.md- Detailed detection patterns and exploitation scenariosexamples.md- Example analysis cases and code samplesreferences.md- CWE references and mitigation strategies