Incorrect Use of Memset Detection

Detection Workflow

1. Identify memset operations: Find all memset() calls, locate buffer clearing operations, identify memory initialization, map sensitive data handling
2. Analyze argument order: Verify memset argument order, check pointer/value/size order, assess argument correctness, review common mistakes
3. Check size calculation: Verify size parameter, check sizeof usage, assess size correctness, review buffer dimensions
4. Assess security impact: Does incorrect memset leave data? Is sensitive data exposed? Can compiler optimize away memset? What's the security impact?

Key Patterns

• Wrong argument order: memset with wrong argument order, size and value arguments swapped, pointer and size arguments swapped, common memset mistakes
• Incorrect size calculation: sizeof on pointer instead of buffer, off-by-one errors in size, size calculation with overflow, wrong size for buffer type
• Misunderstood memset behavior: expecting memset to return filled value, assuming memset validates arguments, thinking memset checks for NULL, misunderstanding memset return value
• Ineffective clearing: memset on optimized-away variables, compiler removing memset calls, incomplete buffer clearing, missing memset on sensitive data

Output Format

Report with: id, type, subtype, severity, confidence, location, vulnerability, memset_call, correct_order, arguments, actual_operation, expected_operation, exploitable, attack_scenario, impact, mitigation.

Severity Guidelines

• HIGH: Incorrect memset leaving sensitive data
• MEDIUM: Incorrect memset causing memory corruption
• LOW: Minor memset errors

See Also

• patterns.md - Detailed detection patterns and exploitation scenarios
• examples.md - Example analysis cases and code samples
• references.md - CWE references and mitigation strategies