Typescript Security Review

TypeScript Security Review

Overview

Security review for TypeScript/Node.js applications. Evaluates code against OWASP Top 10, framework-specific patterns, and production-readiness criteria. Findings are classified by severity (Critical, High, Medium, Low) with remediation examples. Delegates to the typescript-security-expert agent for deep analysis.

When to Use

• Performing security audits on TypeScript/Node.js codebases
• Reviewing authentication and authorization implementations (JWT, OAuth2, Passport.js)
• Checking for common vulnerabilities (XSS, injection, CSRF, path traversal)
• Validating input validation and sanitization logic
• Reviewing dependency security (npm audit, known CVEs)
• Checking secrets management and environment variable handling
• Assessing API security (rate limiting, CORS, security headers)
• Reviewing Express, NestJS, or Next.js security configurations
• Before deploying to production or after significant code changes
• Compliance checks (GDPR, HIPAA, SOC2 data handling requirements)

Instructions

1. Identify Scope: Determine which files and modules are under review. Prioritize authentication, authorization, data handling, API endpoints, and configuration files. Use grep to find security-sensitive patterns (eval, exec, innerHTML, password handling, JWT operations).

   Checkpoint: Verify at least 3 security-sensitive files/modules identified before proceeding.

2. Check Authentication & Authorization: Review JWT implementation (signing algorithm, expiration, refresh tokens), OAuth2/OIDC integration, session management, password hashing (bcrypt/argon2), and multi-factor authentication. Verify protected routes enforce authentication.

   Checkpoint: Use grep to confirm all route handlers have auth guards or middleware applied.

3. Scan for Injection Vulnerabilities: Check for SQL/NoSQL injection in database queries, command injection in exec/spawn, template injection, and LDAP injection. Verify parameterized queries and input validation.

   Checkpoint: Use grep to confirm all database queries use parameterization — no string concatenation with user input.

4. Review Input Validation: Check API inputs validated with Zod, Joi, or class-validator. Verify schema completeness — proper type constraints, length limits, format validation. Check for validation bypass paths.

   Checkpoint: Verify all public API endpoints have corresponding validation schemas.

5. Assess XSS Prevention: Review React components for dangerouslySetInnerHTML usage, check Content Security Policy headers, verify HTML sanitization for user-generated content. See references/xss-prevention.md for detailed patterns.

   Checkpoint: Use grep to confirm any dangerouslySetInnerHTML usage has sanitization via DOMPurify or equivalent.

6. Check Secrets Management: Scan for hardcoded credentials, API keys, secrets in source code. Verify .env files are gitignored, secrets accessed through proper management services.

   Checkpoint: Run grep -r "password\|secret\|api.*key\|token" --include="*.ts" to identify potential secrets in code.

7. Review Dependency Security: Run npm audit or check package-lock.json for known vulnerabilities. Identify outdated dependencies with CVEs. Check for unnecessary dependencies.

   Checkpoint: Verify npm audit results are reviewed and critical vulnerabilities addressed.

8. Evaluate Security Headers & Configuration: Check helmet.js or manual security header configuration. Review CORS policy, rate limiting, HTTPS enforcement, cookie security flags (HttpOnly, Secure, SameSite), and CSP. See references/security-headers.md for configuration examples.

   Checkpoint: Use grep to confirm helmet or equivalent security headers are applied globally.

9. Produce Security Report: Generate structured report with severity-classified findings, remediation guidance with code examples, and security posture summary.

   Feedback Loop: If Critical or High vulnerabilities found, re-scan related modules for similar patterns before finalizing. Use grep to identify if the same vulnerability pattern exists elsewhere.

Examples

JWT Security Review

// ❌ Critical: Weak JWT configuration
import jwt from 'jsonwebtoken';

const SECRET = 'mysecret123'; // Hardcoded weak secret

function generateToken(user: User) {
  return jwt.sign({ id: user.id, role: user.role }, SECRET);
  // Missing expiration, weak secret, no algorithm specification
}

// ✅ Secure: Proper JWT configuration
import jwt from 'jsonwebtoken';

const JWT_SECRET = process.env.JWT_SECRET;
if (!JWT_SECRET || JWT_SECRET.length < 32) {
  throw new Error('JWT_SECRET must be set and at least 32 characters');
}

function generateToken(user: User): string {
  return jwt.sign(
    { sub: user.id }, // Minimal claims, no sensitive data
    JWT_SECRET,
    {
      algorithm: 'HS256',
      expiresIn: '15m',
      issuer: 'my-app',
      audience: 'my-app-client',
    }
  );
}

function verifyToken(token: string): JwtPayload {
  return jwt.verify(token, JWT_SECRET, {
    algorithms: ['HS256'], // Restrict accepted algorithms
    issuer: 'my-app',
    audience: 'my-app-client',
  }) as JwtPayload;
}

SQL Injection Prevention

// ❌ Critical: SQL injection vulnerability
async function findUser(email: string) {
  const result = await db.query(
    `SELECT * FROM users WHERE email = '${email}'`
  );
  return result.rows[0];
}

// ✅ Secure: Parameterized query
async function findUser(email: string) {
  const result = await db.query(
    'SELECT id, name, email FROM users WHERE email = $1',
    [email]
  );
  return result.rows[0];
}

// ✅ Secure: ORM with type-safe queries (Drizzle example)
async function findUser(email: string) {
  return db.select({
    id: users.id,
    name: users.name,
    email: users.email,
  })
  .from(users)
  .where(eq(users.email, email))
  .limit(1);
}

See references/xss-prevention.md for XSS patterns and references/security-headers.md for security headers configuration.