Security Review Skill

OWASP Top 10 (2021) Checklist

A01: Broken Access Control

• Authorization checks on every endpoint
• Deny by default policy
• CORS properly configured
• Directory listing disabled
• JWT tokens validated server-side

A02: Cryptographic Failures

• No sensitive data in URLs
• HTTPS enforced everywhere
• Strong encryption algorithms (AES-256, RSA-2048+)
• Passwords hashed with bcrypt/argon2
• No hardcoded secrets

A03: Injection

• Parameterized queries for SQL
• Input validation and sanitization
• Output encoding for context
• No eval() or dynamic code execution
• Command arguments properly escaped

A04: Insecure Design

• Threat modeling completed
• Rate limiting implemented
• Resource quotas enforced
• Fail securely (deny on error)

A05: Security Misconfiguration

• Default credentials changed
• Debug mode disabled in production
• Error messages don't leak info
• Security headers configured
• Unnecessary features disabled

A06: Vulnerable Components

• Dependencies up to date
• No known CVEs in dependencies
• Dependency audit in CI/CD
• License compliance checked

A07: Authentication Failures

• Multi-factor authentication available
• Strong password policy
• Account lockout after failures
• Secure session management
• Password reset is secure

A08: Data Integrity Failures

• Code signing in place
• CI/CD pipeline secured
• Deserialization validated
• Update mechanisms secure

A09: Logging & Monitoring

• Security events logged
• Logs don't contain sensitive data
• Alerting on suspicious activity
• Log integrity protected

A10: SSRF

• URL validation for external requests
• Allowlist for permitted hosts
• No raw URL from user input
• Metadata endpoints blocked

Code Patterns to Flag

# DANGEROUS: SQL Injection
cursor.execute(f"SELECT * FROM users WHERE id = {user_id}")

# SAFE: Parameterized query
cursor.execute("SELECT * FROM users WHERE id = %s", (user_id,))

// DANGEROUS: XSS
element.innerHTML = userInput;

// SAFE: Text content
element.textContent = userInput;

# DANGEROUS: Command injection
os.system(f"ping {hostname}")

# SAFE: Use subprocess with list
subprocess.run(["ping", hostname], check=True)

Security Headers

Content-Security-Policy: default-src 'self'
X-Frame-Options: DENY
X-Content-Type-Options: nosniff
Strict-Transport-Security: max-age=31536000; includeSubDomains
Referrer-Policy: strict-origin-when-cross-origin
Permissions-Policy: geolocation=(), microphone=()

Severity Classification