security-auditor skill

---
name: security-auditor
description: Continuous security vulnerability scanning for OWASP Top 10, common vulnerabilities, and insecure patterns. Use when reviewing code, before deployments, or on file changes. Scans for SQL injection, XSS, secrets exposure, auth issues. Triggers on file changes, security mentions, deployment prep.
allowed-tools: Read, Grep, Bash
---

# Security Auditor Skill

Automatic security vulnerability detection.

## When I Activate

- ✅ Code files modified (especially auth, API, database)
- ✅ User mentions security or vulnerabilities
- ✅ Before deployments or commits
- ✅ Dependency changes
- ✅ Configuration file changes

## What I Scan For

### OWASP Top 10 Patterns

**1. SQL Injection**
```javascript
// CRITICAL: SQL injection
const query = `SELECT * FROM users WHERE id = ${userId}`;

// SECURE: Parameterized query
const query = 'SELECT * FROM users WHERE id = ?';
db.query(query, [userId]);
```

**2. XSS (Cross-Site Scripting)**
```javascript
// CRITICAL: XSS vulnerability
element.innerHTML = userInput;

// SECURE: Use textContent or sanitize
element.textContent = userInput;
// or
element.innerHTML = DOMPurify.sanitize(userInput);
```

**3. Authentication Issues**
```javascript
// CRITICAL: Weak JWT secret
const token = jwt.sign(payload, 'secret123');

// SECURE: Strong secret from environment
const token = jwt.sign(payload, process.env.JWT_SECRET);
```

**4. Sensitive Data Exposure**
```python
# CRITICAL: Exposed password
password = "admin123"

# SECURE: Environment variable
password = os.getenv("DB_PASSWORD")
```

**5. Broken Access Control**
```javascript
// CRITICAL: No authorization check
app.delete('/api/users/:id', (req, res) => {
  User.delete(req.params.id);
});

// SECURE: Authorization check
app.delete('/api/users/:id', auth, checkOwnership, (req, res) => {
  User.delete(req.params.id);
});
```

### Additional Security Checks

- **Insecure Deserialization**
- **Security Misconfiguration**
- **Insufficient Logging**
- **CSRF Protection Missing**
- **CORS Misconfiguration**

## Alert Format

```
🚨 CRITICAL: [Vulnerability type]
📍 Location: file.js:42
🔧 Fix: [Specific remediation]
📖 Reference: [OWASP/CWE link]
```

### Severity Levels

- 🚨 **CRITICAL**: Must fix immediately (exploitable vulnerabilities)
- ⚠️ **HIGH**: Should fix soon (security weaknesses)
- 📋 **MEDIUM**: Consider fixing (potential issues)
- 💡 **LOW**: Best practice improvements

## Real-World Examples

### SQL Injection Detection

```javascript
// You write:
app.get('/users', (req, res) => {
  const sql = `SELECT * FROM users WHERE name = '${req.query.name}'`;
  db.query(sql, (err, results) => res.json(results));
});

// I alert:
🚨 CRITICAL: SQL injection vulnerability (line 2)
📍 File: routes/users.js, Line 2
🔧 Fix: Use parameterized queries
  const sql = 'SELECT * FROM users WHERE name = ?';
  db.query(sql, [req.query.name], ...);
📖 https://owasp.org/www-community/attacks/SQL_Injection
```

### Password Storage

```python
# You write:
def create_user(username, password):
    user = User(username=username, password=password)
    user.save()

# I alert:
🚨 CRITICAL: Storing plain text password (line 2)
📍 File: models.py, Line 2
🔧 Fix: Hash passwords before storing
  from bcrypt import hashpw, gensalt
  hashed = hashpw(password.encode(), gensalt())
  user = User(username=username, password=hashed)
📖 Use bcrypt, scrypt, or argon2 for password hashing
```

### API Key Exposure

```javascript
// You write:
const stripe = require('stripe')('sk_live_abc123...');

// I alert:
🚨 CRITICAL: Hardcoded API key detected (line 1)
📍 File: payment.js, Line 1
🔧 Fix: Use environment variables
  const stripe = require('stripe')(process.env.STRIPE_SECRET_KEY);
📖 Never commit API keys to version control
```

## Dependency Scanning

I can run security audits on dependencies:

```bash
# Node.js
npm audit

# Python
pip-audit

# Results flagged with severity
```

## Relationship with @code-reviewer Sub-Agent

**Me (Skill):** Quick vulnerability pattern detection
**@code-reviewer (Sub-Agent):** Deep security audit with threat modeling

### Workflow
1. I detect vulnerability pattern
2. I flag: "🚨 SQL injection detected"
3. You want full analysis → Invoke **@code-reviewer** sub-agent
4. Sub-agent provides comprehensive security audit

## Common Vulnerability Patterns

### Authentication
- Weak password policies
- Missing MFA
- Session fixation
- Insecure password storage

### Authorization
- Missing access control
- Privilege escalation
- IDOR (Insecure Direct Object Reference)

### Data Protection
- Unencrypted sensitive data
- Weak encryption algorithms
- Missing HTTPS
- Insecure cookies

### Input Validation
- SQL injection
- Command injection
- XSS
- Path traversal

## Sandboxing Compatibility

**Works without sandboxing:** ✅ Yes
**Works with sandboxing:** ✅ Yes

**Optional: For dependency scanning**
```json
{
  "network": {
    "allowedDomains": [
      "registry.npmjs.org",
      "pypi.org",
      "api.github.com"
    ]
  }
}
```

## Integration with Tools

### With secret-scanner Skill
```
security-auditor: Checks code patterns
secret-scanner: Checks for exposed secrets
Together: Comprehensive security coverage
```

### With /review Command
```bash
/review --scope staged --checks security

# Workflow:
# 1. My automatic security findings
# 2. @code-reviewer sub-agent deep audit
# 3. Comprehensive security report
```

## Customization

Add company-specific security patterns:

```bash
cp -r ~/.claude/skills/security/security-auditor \
      ~/.claude/skills/security/company-security-auditor

# Edit SKILL.md to add:
# - Internal API patterns
# - Company security policies
# - Custom vulnerability checks
```

## Learn More

- [OWASP Top 10](https://owasp.org/www-project-top-ten/)
- [CWE Top 25](https://cwe.mitre.org/top25/)
- [Security Best Practices](../../standards/security/)