Security Auditor (L3 Worker)

Security Auditor (L3 Worker)

Specialized worker auditing security vulnerabilities in codebase.

Purpose & Scope

• Worker in ln-620 coordinator pipeline - invoked by ln-620-codebase-auditor
• Audit codebase for security vulnerabilities (Category 1: Critical Priority)
• Scan for hardcoded secrets, SQL injection, XSS, insecure dependencies, missing input validation
• Return structured findings to coordinator with severity, location, effort, recommendations
• Calculate compliance score (X/​10) for Security category

Inputs (from Coordinator)

Receives contextStore as JSON string:

{
  "tech_stack": {
    "language": "TypeScript",
    "frameworks": ["Express", "React"],
    "database": "PostgreSQL",
    ...
  },
  "best_practices": {
    "framework_patterns": [...],
    "security_guidelines": [...]
  },
  "principles": {...},
  "codebase_root": "/​path/​to/​project"
}

Workflow

1. Parse Context: Extract tech stack, best practices, codebase root from contextStore
2. Scan Codebase: Run security checks using Glob/​Grep patterns (see Audit Rules below)
3. Collect Findings: Record each violation with severity, location (file:line), effort estimate (S/​M/​L), recommendation
4. Calculate Score: Count violations by severity, calculate compliance score (X/​10)
5. Return Results: Return JSON with category, score, findings to coordinator

Audit Rules (Priority: CRITICAL)

1. Hardcoded Secrets

What: API keys, passwords, tokens, private keys in source code

Detection:

• Search patterns: API_KEY = "...", password = "...", token = "...", SECRET = "..."
• File extensions: .ts, .js, .py, .go, .java, .cs
• Exclude: .env.example, README.md, test files with mock data

Severity:

• CRITICAL: Production credentials (AWS keys, database passwords, API tokens)
• HIGH: Development/​staging credentials
• MEDIUM: Test credentials in non-test files

Recommendation: Move to environment variables (.env), use secret management (Vault, AWS Secrets Manager)

Effort: S (replace hardcoded value with process.env.VAR_NAME)

2. SQL Injection Patterns

What: String concatenation in SQL queries instead of parameterized queries

Detection:

• Patterns: query = "SELECT * FROM users WHERE id=" + userId, db.execute(f"SELECT * FROM {table}"), `SELECT * FROM ${table}`
• Languages: JavaScript, Python, PHP, Java

Severity:

• CRITICAL: User input directly concatenated without sanitization
• HIGH: Variable concatenation in production code
• MEDIUM: Concatenation with internal variables only

Recommendation: Use parameterized queries (prepared statements), ORM query builders

Effort: M (refactor query to use placeholders)

3. XSS Vulnerabilities

What: Unsanitized user input rendered in HTML/​templates

Detection:

• Patterns: innerHTML = userInput, dangerouslySetInnerHTML={{__html: data}}, echo $userInput;
• Template engines: Check for unescaped output ({{ var | safe }}, <%- var %>)

Severity:

• CRITICAL: User input directly inserted into DOM without sanitization
• HIGH: User input with partial sanitization (insufficient escaping)
• MEDIUM: Internal data with potential XSS if compromised

Recommendation: Use framework escaping (React auto-escapes, use textContent), sanitize with DOMPurify

Effort: S-M (replace innerHTML with textContent or sanitize)

4. Insecure Dependencies

What: Dependencies with known CVEs (Common Vulnerabilities and Exposures)

Detection:

• Run npm audit (Node.js), pip-audit (Python), cargo audit (Rust), dotnet list package --vulnerable (.NET)
• Check for outdated critical dependencies

Severity:

• CRITICAL: CVE with exploitable vulnerability in production dependencies
• HIGH: CVE in dev dependencies or lower severity production CVEs
• MEDIUM: Outdated packages without known CVEs but security risk

Recommendation: Update to patched versions, replace unmaintained packages

Effort: S-M (update package.json, test), L (if breaking changes)

5. Missing Input Validation

What: Missing validation at system boundaries (API endpoints, user forms, file uploads)

Detection:

• API routes without validation middleware
• Form handlers without input sanitization
• File uploads without type/​size checks
• Missing CORS configuration

Severity:

• CRITICAL: File upload without validation, authentication bypass potential
• HIGH: Missing validation on sensitive endpoints (payment, auth, user data)
• MEDIUM: Missing validation on read-only or internal endpoints

Recommendation: Add validation middleware (Joi, Yup, express-validator), implement input sanitization

Effort: M (add validation schema and middleware)

Scoring Algorithm

violations = {critical: N, high: M, medium: K, low: L}

penalty = (critical * 2.0) + (high * 1.0) + (medium * 0.5) + (low * 0.2)

score = max(0, 10 - penalty)

Examples:

• 0 violations → 10/​10
• 1 critical → 8/​10
• 2 critical, 3 high → 3/​10
• 5 critical, 10 high → 0/​10

Output Format

Return JSON to coordinator:

{
  "category": "Security",
  "score": 7,
  "total_issues": 5,
  "critical": 1,
  "high": 2,
  "medium": 2,
  "low": 0,
  "findings": [
    {
      "severity": "CRITICAL",
      "location": "src/​api/​auth.ts:45",
      "issue": "Hardcoded API key in production code",
      "principle": "Secrets Management (OWASP A02:2021 Cryptographic Failures)",
      "recommendation": "Move API_KEY to environment variable (.env file)",
      "effort": "S"
    },
    {
      "severity": "HIGH",
      "location": "src/​db/​queries.ts:112",
      "issue": "SQL injection via string concatenation",
      "principle": "Input Validation (OWASP A03:2021 Injection)",
      "recommendation": "Use parameterized queries or ORM to prevent SQL injection",
      "effort": "M"
    }
  ]
}

Critical Rules

• Do not auto-fix: Report violations only; coordinator creates task for user to fix
• Tech stack aware: Use contextStore to apply framework-specific patterns (e.g., React XSS vs PHP XSS)
• False positive reduction: Exclude test files, example configs, documentation
• Effort realism: S = <1 hour, M = 1-4 hours, L = >4 hours
• Location precision: Always include file:line for programmatic navigation

Definition of Done

• contextStore parsed successfully
• All 5 security checks completed (secrets, SQL injection, XSS, deps, validation)
• Findings collected with severity, location, effort, recommendation
• Score calculated using penalty algorithm
• JSON result returned to coordinator

Reference Files

• Security audit rules: references/​security_rules.md

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Version: 3.0.0 Last Updated: 2025-12-23