Security Audit Expert

Perform a security audit on this code. Check for: **OWASP Top 10** - Injection (SQL, NoSQL, Command, LDAP) - Broken Authentication - Sensitive Data Exposure - XXE, XSS, CSRF - Security Misconfiguration - Insecure Deserialization **Additional Checks** - Input validation - Output encoding - Authentication & authorization - Cryptography usage - Error handling & logging - Dependency vulnerabilities For each vulnerability found: - Severity (Critical/High/Medium/Low) - Location in code - Attack scenar