Security Auditor (L3 Worker) Skill

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Security Auditor (L3 Worker)

Type: L3 Worker

Specialized worker auditing security vulnerabilities in codebase.

Purpose & Scope

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

MANDATORY READ: Load shared/references/audit_worker_core_contract.md.

Receives contextStore with: tech_stack, best_practices, principles, codebase_root, output_dir.

Workflow

MANDATORY READ: Load shared/references/two_layer_detection.md for detection methodology.

Parse Context: Extract tech stack, best practices, codebase root, output_dir from contextStore
Scan Codebase (Layer 1): Run security checks using Glob/Grep patterns (see Audit Rules below)
Analyze Context (Layer 2): For each candidate, read surrounding code to classify:
- Secrets: test fixture / example / template -> FP. Production code -> confirmed
- SQL injection: ORM parameterization nearby -> FP. Raw string concat with user input -> confirmed
- XSS: framework auto-escapes (React JSX, Go templates) -> FP. Unsafe context (innerHTML, | safe) -> confirmed
- Deps: vulnerable API not called in project -> downgrade. Exploitable path -> confirmed
- Validation: internal service-to-service endpoint -> downgrade. Public API -> confirmed
Collect Findings: Record confirmed violations with severity, location (file:line), effort estimate (S/M/L), recommendation
Calculate Score: Count violations by severity, calculate compliance score (X/10)
Write Report: Build full markdown report in memory per shared/templates/audit_worker_report_template.md, write to {output_dir}/ln-621--global.md in single Write call
Return Summary: Return minimal summary to coordinator (see Output Format)

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

MANDATORY READ: Load shared/references/audit_worker_core_contract.md and shared/references/audit_scoring.md.

Output Format

MANDATORY READ: Load shared/references/audit_worker_core_contract.md and shared/templates/audit_worker_report_template.md.

Write JSON summary per shared/references/audit_summary_contract.md. In managed mode the caller passes both runId and summaryArtifactPath; in standalone mode the worker generates its own run-scoped artifact path per shared contract.

Write report to {output_dir}/ln-621--global.md with category: "Security" and checks: hardcoded_secrets, sql_injection, xss_vulnerabilities, insecure_dependencies, missing_input_validation.

Return summary per shared/references/audit_summary_contract.md.

Standalone mode still writes the same JSON summary to a worker-owned run-scoped artifact path per shared contract.

Critical Rules

MANDATORY READ: Load shared/references/audit_worker_core_contract.md.

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

MANDATORY READ: Load shared/references/audit_worker_core_contract.md.

[ ] contextStore parsed successfully (including output_dir)
[ ] All 5 security checks completed (secrets, SQL injection, XSS, deps, validation)
[ ] Findings collected with severity, location, effort, recommendation
[ ] Score calculated using penalty algorithm
[ ] Report written to {output_dir}/ln-621--global.md (atomic single Write call)
[ ] Summary written per contract

Reference Files

Audit output schema: shared/references/audit_output_schema.md
Security audit rules: references/security_rules.md

Version: 3.0.0 Last Updated: 2025-12-23

Agent Skills: Security Auditor (L3 Worker)

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