# Security Expert

> Expert in application security, OWASP Top 10, authentication, authorization, data protection, and security best practices for React, Next.js, and NestJS applications. Use when implementing authentication or authorization, reviewing code for vulnerabilities, handling sensitive data, or implementing encryption or hashing.

- Skill: `shipshitdev/security-expert` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds add shipshitdev/security-expert`
- Raw SKILL.md: https://api.skillmd.com/api/skills/shipshitdev/security-expert/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Web & Frontend
- Author: shipshitdev (https://skillmd.com/u/shipshitdev)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/shipshitdev/security-expert

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# Security Expert Skill

## When to Use

- Implementing authentication or authorization
- Reviewing code for security vulnerabilities
- Setting up security configurations
- Handling sensitive data
- Implementing encryption or hashing
- Configuring CORS, CSP, or security headers
- Reviewing dependencies for vulnerabilities
- Implementing multi-tenancy or data isolation

## Project Context Discovery

1. Check `.agents/memory/` for security architecture notes and project facts
2. Review the applicable `AGENTS.override.md` / `AGENTS.md` chain and any explicitly configured fallback instruction file; include `CLAUDE.md` only for Claude-specific rules
3. Identify security patterns and tools
4. Check for `[project]-security-expert` skill

## Core Security Principles

### Authentication & Authorization

**Authentication:** Secure password hashing (bcrypt/argon2), JWT management, session security, MFA, OAuth/SSO

**Authorization:** RBAC, permission checks on all endpoints, resource-level auth, multi-tenancy enforcement

### Input Validation

- DTOs with class-validator
- Sanitize user input
- Prevent NoSQL/SQL injection
- Parameterized queries

### Data Protection

- Encryption at rest and in transit
- Passwords hashed (never plaintext)
- Environment variables for secrets
- No secrets in code

### Security Headers

- X-Content-Type-Options: nosniff
- X-Frame-Options: DENY
- Strict-Transport-Security
- Content Security Policy

## OWASP Top 10 Quick Reference

1. **Broken Access Control:** Verify auth on all endpoints
2. **Cryptographic Failures:** Strong encryption, proper hashing
3. **Injection:** Parameterized queries, input validation
4. **Insecure Design:** Security by design, threat modeling
5. **Security Misconfiguration:** Secure defaults, remove unused features
6. **Vulnerable Components:** Keep dependencies updated
7. **Authentication Failures:** Strong passwords, MFA, brute force protection
8. **Integrity Failures:** Secure CI/CD, code signing
9. **Logging Failures:** Comprehensive logging, monitoring
10. **SSRF:** Validate URLs, whitelist domains

## Security Checklist Summary

- [ ] Passwords hashed (bcrypt/argon2)
- [ ] All endpoints protected
- [ ] Multi-tenancy enforced
- [ ] All inputs validated
- [ ] Encryption at rest/transit
- [ ] Security headers configured
- [ ] CORS properly configured
- [ ] Dependencies up to date

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**For complete authentication/authorization patterns, input validation examples, OWASP prevention techniques, framework-specific security (React/Next.js/NestJS), MongoDB security, AWS security, and detailed security checklists, see:** `references/full-guide.md`