Security-Focused Code Review

Review this {{language}} code specifically for security vulnerabilities:

```
{{paste your code}}
```

Check for:
1. Injection attacks (SQL, XSS, command injection, path traversal)
2. Authentication/authorization flaws
3. Sensitive data exposure (logging secrets, hardcoded credentials)
4. Insecure deserialization
5. Missing input validation at trust boundaries

For each vulnerability found:
- Name the vulnerability type (e.g., "CWE-89: SQL Injection")
- Show the vulnerable line
- Explain the attack scenario
- Provide the fixed code

If no vulnerabilities are found, confirm the code is clean and note what was checked.