How to Automate Security Audits with Claude Code

Streamline Security Audits with AI

Security reviews require specialized knowledge and are time-consuming. With Claude Code, you can automate everything from detecting common vulnerability patterns to suggesting fixes.

Basic Security Scan

> Perform a security audit of the entire project.
> Check for the following:
> - SQL injection
> - XSS (cross-site scripting)
> - CSRF
> - Authentication and authorization issues
> - Hard-coded secrets
> - Dependency vulnerabilities

Detecting and Fixing Vulnerability Patterns

SQL Injection

// Vulnerable code
const query = `SELECT * FROM users WHERE email = '${email}'`;
const result = await db.query(query);

// Fix by Claude Code: parameterized query
const result = await db.query(
  "SELECT * FROM users WHERE email = $1",
  [email]
);

XSS (Cross-Site Scripting)

// Vulnerable code
element.innerHTML = userInput;

// Fix by Claude Code: sanitize
import DOMPurify from "dompurify";
element.innerHTML = DOMPurify.sanitize(userInput);

// Or insert as text
element.textContent = userInput;

Preventing Secret Leaks

> Search the project for any hard-coded API keys, passwords,
> or tokens. Replace any found with environment variables.

// Before fix: hard-coded
const API_KEY = "sk-1234567890abcdef";

// After fix: environment variable
const API_KEY = process.env.API_KEY;
if (!API_KEY) {
  throw new Error("API_KEY environment variable is required");
}

Checking Dependency Vulnerabilities

> Run npm audit. If vulnerabilities are found,
> update the versions to fix them.
> Verify there are no breaking changes.

# Commands Claude Code would run
npm audit
npm audit fix
# Manually address items that can't be auto-fixed
npm install package-name@latest
npm test  # Run tests after updating

Authentication and Authorization Audit

> Audit authentication and authorization checks on API endpoints.
> Identify unprotected endpoints and fix them.

// Before fix: no authentication check
router.delete("/users/:id", async (req, res) => {
  await deleteUser(req.params.id);
  res.status(204).send();
});

// After fix: authentication + authorization check
router.delete("/users/:id",
  authenticate,
  authorize("admin"),
  async (req, res) => {
    await deleteUser(req.params.id);
    res.status(204).send();
  }
);

OWASP Top 10 Checklist

You can also have Claude Code perform a systematic check.

> Perform a security check on this application
> based on the OWASP Top 10 (2021).
> Report any issues found for each item.

Configuring Security Headers

> Configure the necessary security headers
> for the web application. Use Helmet.

import helmet from "helmet";

app.use(helmet({
  contentSecurityPolicy: {
    directives: {
      defaultSrc: ["'self'"],
      scriptSrc: ["'self'"],
      styleSrc: ["'self'", "'unsafe-inline'"],
      imgSrc: ["'self'", "data:", "https:"],
    },
  },
  hsts: { maxAge: 31536000, includeSubDomains: true },
  referrerPolicy: { policy: "strict-origin-when-cross-origin" },
}));

.env File Security

> Generate a .env.example from .env.
> Replace actual values with placeholders.
> Verify that .env is included in .gitignore.

# .env.example (generated by Claude Code)
DATABASE_URL=postgresql://user:password@localhost:5432/dbname
JWT_SECRET=your-secret-key-here
API_KEY=your-api-key-here
REDIS_URL=redis://localhost:6379

For security perspectives in code reviews, see Streamlining Code Reviews with AI. For integrating security scans into CI/CD, see the CI/CD Pipeline Guide. For preventing information leaks through error handling, also check out Error Handling Design Patterns.

Summary

Security audits with Claude Code can efficiently detect common vulnerabilities. However, AI-powered audits are not infallible. For production environments, be sure to combine them with dedicated security scanning tools and expert reviews.

For security best practices, refer to the official OWASP website. For Claude Code, see the official Anthropic documentation.