OWASP Security skill

---
name: owasp-security
description: Reviews code for security vulnerabilities and guides secure implementation using OWASP Top 10:2025, ASVS 5.0, the OWASP Top 10 for LLM Applications (2026), and the OWASP Top 10 for Agentic Applications (2026). Use when reviewing code or a diff for security issues, implementing authentication, authorization, sessions, or cryptography, handling untrusted input, files, or URLs, hardening config, dependencies, or CI, or building LLM and AI agent features.
when_to_use: Trigger phrases include "security review", "security check", "anything exploitable", "audit this", "is this secure", "is this safe to ship", "check for vulnerabilities", "find security bugs", "threat model", "OWASP", "ASVS", "CWE", "prompt injection", "MCP server security", "secrets in code", "supply chain", and "harden this Dockerfile or workflow".
---

# OWASP Security

Apply these standards when writing or reviewing code. For a review, follow the workflow below.

**Reference files** (read the one the task needs, and only the section you need):
- [`reference/review-checklist.md`](reference/review-checklist.md): coverage checklist for every Top 10 category, plus LLM and agent checks. Read during step 3 of a review.
- [`reference/languages.md`](reference/languages.md): per-language pitfalls with unsafe/safe examples for 20+ languages. Read the section for the language under review.
- [`reference/config-and-supply-chain.md`](reference/config-and-supply-chain.md): A02 and A03 in Dockerfiles, Kubernetes, Terraform, framework config, security headers, lockfiles, and CI/CD. Read when the change touches config, IaC, dependencies, or pipelines.
- [`reference/owasp-report.md`](reference/owasp-report.md): attack vectors, mitigations, and worked examples for every Top 10:2025, ASVS 5.0, LLM Top 10, and Agentic item. About 1100 lines: jump to the section you need.

## Security Review Workflow

Copy this checklist into your response and tick it off as you go:

```
Security Review Progress:
- [ ] Step 1: Map entry points and trust boundaries
- [ ] Step 2: Load the references this code needs
- [ ] Step 3: Sweep for candidate issues
- [ ] Step 4: Triage every candidate
- [ ] Step 5: Report findings
```

**Step 1: Map entry points and trust boundaries.** List where attacker-controlled data enters:
routes and handlers, headers and cookies, uploads, webhooks, queue consumers, CLI arguments,
third-party API responses, and anything an LLM reads or returns. Note where authentication and
authorization are enforced; it is often centralized in middleware rather than per route.

**Step 2: Load the references this code needs.** The language section of `languages.md`;
`config-and-supply-chain.md` if config, IaC, dependencies, or CI changed; the LLM and Agentic
sections of `owasp-report.md` if the code calls a model or runs an agent.

**Step 3: Sweep for candidate issues.** Walk `review-checklist.md` for the categories the code
touches. For each candidate, trace the path from an entry point in step 1 to the sink.

**Step 4: Triage every candidate** with the rubric in "Before Reporting a Finding" below. Drop
candidates that fail it, or downgrade them to defense-in-depth. If a candidate's reachability
is unclear, go back to step 1 for that input before deciding.

**Step 5: Report findings** in the format below, highest severity first.

## Before Reporting a Finding