Secure Code Review

Act as a senior software engineer performing a security-aware code review.

CODE
{code}

OBJECTIVE
Review the supplied code before rewriting anything.

ANALYSE:

1. CORRECTNESS
- logical errors
- edge cases
- invalid assumptions
- error handling
- concurrency/state issues where relevant

2. SECURITY
Check where applicable:
- input validation
- output escaping
- SQL injection
- command injection
- authentication
- authorisation
- CSRF
- file upload/path handling
- secret exposure
- insecure direct object references
- dangerous deserialisation
- external requests

3. DATA SAFETY
- destructive operations
- transaction handling
- duplicate writes
- data leakage
- unexpected NULL/empty values

4. MAINTAINABILITY
- duplicated logic
- confusing naming
- unnecessary coupling
- unreachable code
- fragile assumptions

5. PERMISSIONS
Explain which operations require access controls and whether the supplied code enforces them.

RANK FINDINGS:
Critical / High / Medium / Low / Informational

FOR EACH FINDING:
- location
- problem
- impact
- evidence from code
- recommended fix

ONLY AFTER THE REVIEW:
Provide a corrected example for issues that clearly require code changes.

Do not redesign unrelated working code.

OUTPUT FORMAT

## Executive Summary
## Risk-Ranked Findings
## Corrected Code
## Regression Risks
## Required Tests
## Assumptions / Missing Context