Taint Analysis

Detection Workflow

1. Identify sources: Find recv, read, getenv, fgets, scanf, argv (input functions)
2. Identify sinks: Find system, popen, strcpy, sprintf, execve, malloc (dangerous functions)
3. Find taint paths: Use xrefs_to to trace from sources to sinks
4. Analyze sanitization: Check for input validation, length checks, character filtering, encoding/escaping
5. Assess risk: Determine reachability, check if attacker controls critical parts, evaluate exploitability

Key Patterns

• Direct command injection: recv() -> buffer -> sprintf(cmd, "echo %s", buffer) -> system(cmd)
• Path traversal: fgets() -> filename -> fopen(filename, "r")
• Buffer overflow via tainted size: recv() -> size_buffer -> atoi(size_buffer) -> malloc(size)

Output Format

Report taint paths with: source (function, address, context), sink (function, address, context), path (list of functions), sanitizers_found, is_vulnerable, confidence, vulnerability_type.

Severity Guidelines

• CRITICAL: Direct injection with no sanitization (command injection, SQL injection)
• HIGH: Path traversal, buffer overflow via tainted size
• MEDIUM: Potential injection with partial sanitization
• LOW: Tainted data with limited impact

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