Securing Your Code with Claude Code Skills

Security is often treated at the end of a project — too late. With the right skills, Claude Code integrates security from the first line of code.

The Problem: Security as an Afterthought

Most vulnerabilities are introduced during development:

• SQL injection in dynamic queries
• XSS in unescaped templates
• CSRF without validation tokens
• Hardcoded secrets in code

Claude Code, without specific instructions, can reproduce these mistakes. Security skills fix that.

Essential Security Skills

VibeSec Skill — Automatic Auditing

Score: 70/100 | The Guardian

VibeSec transforms Claude into a security auditor that:

• Scans code for OWASP Top 10 vulnerabilities
• Suggests fixes with code
• Checks security headers
• Analyzes dependencies for known CVEs

Security Code Auditor — Deep Analysis

Multi-platform | The Expert

A skill dedicated to security analysis:

• XSS, SQL injection, SSRF detection
• Authentication flow analysis
• Encryption verification
• Compliance auditing

Integrated Security Checklist

1. Input Validation

Claude should always validate user input:

// ❌ Vulnerable to SQL injection
const user = await db.query(`SELECT * FROM users WHERE id = ${req.params.id}`);

// ✅ Parameterized query
const user = await db.query('SELECT * FROM users WHERE id = $1', [req.params.id]);

2. Output Escaping

Any data displayed in HTML must be escaped:

// ❌ Vulnerable to XSS
<div>{userInput}</div>

// ✅ React escapes by default, but watch out for dangerouslySetInnerHTML
<div>{sanitize(userInput)}</div>

3. Authentication and Authorization

// ❌ Insufficient check
if (req.session.userId) { /* access granted */ }

// ✅ Check role AND resource
if (req.session.userId && await canAccess(req.session.userId, resourceId)) {
  /* access granted */
}

4. Secrets Management

# ❌ Never hardcode secrets
const API_KEY = "sk-123456789";

# ✅ Environment variables
const API_KEY = process.env.API_KEY;

5. Security Headers

// Configure in your middleware or next.config.js
const securityHeaders = {
  'X-Content-Type-Options': 'nosniff',
  'X-Frame-Options': 'DENY',
  'X-XSS-Protection': '1; mode=block',
  'Strict-Transport-Security': 'max-age=31536000; includeSubDomains',
  'Content-Security-Policy': "default-src 'self'",
};

Recommended Security Workflow

1. During development: VibeSec active at all times
2. Before each PR: Security Code Auditor audit
3. Weekly: Dependency scan (npm audit)
4. Monthly: Complete review of permissions and access

Integration with Other Skills

Combination	Benefit
VibeSec + Playwright	Security E2E tests
Security Auditor + Git Workflow	Audit before each commit
VibeSec + Next.js Expert	Secure SSR

Mistakes Claude Code Catches

With security skills activated, Claude detects:

• ✅ SQL and NoSQL injections
• ✅ XSS (stored, reflected, DOM-based)
• ✅ CSRF without protection
• ✅ Secrets in source code
• ✅ Vulnerable dependencies
• ✅ Overly broad permissions
• ✅ Missing security headers

Conclusion

Security isn't an optional skill — it's a foundation. Install VibeSec and Security Code Auditor now, and let Claude catch vulnerabilities before they reach production.