# Common Owasp

> OWASP Top 10 audit checklist for Web Applications (2021) and APIs (2023). Load during any security review, PR review, or codebase audit touching web, mobile backend, or API code. (triggers: security review, OWASP, broken access control, IDOR, BOLA, injection, broken auth, API review, authorization, access control)

- Skill: `comeonoliver/common-owasp` (Agent Skill)
- Install (CLI): `npx skillmds@latest add comeonoliver/common-owasp`
- Raw SKILL.md: https://api.skillmd.com/api/skills/comeonoliver/common-owasp/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: ComeOnOliver (https://skillmd.com/u/comeonoliver)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/comeonoliver/common-owasp

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# OWASP Top 10 Security Checklist

## **Priority: P0 (CRITICAL)**

## Implementation Guidelines

- **Check A01/API1 first**: IDOR is the #1 finding in real codebases — any `findById(userInput)` without an owner/tenant filter is an immediate P0.
- **Mark each item**: ✅ not affected | ⚠️ needs review | 🔴 confirmed finding.
- **P0 finding caps Security score at 40/100** — do not skip any item.
- Apply framework-specific security skills alongside this checklist.
- See [references/owasp-web.md](references/owasp-web.md) and [references/owasp-api.md](references/owasp-api.md) for full detection signals per item.

## OWASP Web Application Top 10 (2021)

| ID  | Risk | Key Detection Signal |
| --- | ---- | -------------------- |
| A01 | Broken Access Control | `findById(params.id)` without owner filter. Route without `@authorize`. |
| A02 | Cryptographic Failures | Weak hash (MD5/SHA1) for passwords. HTTP URL hardcoded. No TLS. |
| A03 | Injection | String concat in DB queries. Unsanitized input to templates. XSS. |
| A04 | Insecure Design | No rate limiting on auth. Missing input validation at entry points. |
| A05 | Security Misconfiguration | CORS `*`. Debug mode in prod. Missing security headers (CSP, HSTS). |
| A06 | Vulnerable Components | CVE in dependency audit. Unreviewed new direct dependency. |
| A07 | Auth Failures | JWT without expiry. No session invalidation on logout. |
| A08 | Data Integrity Failures | Unverified JWT/cookie. Deserialization of untrusted input. |
| A09 | Logging & Monitoring | No audit log on: deletion, password change, privilege escalation. |
| A10 | SSRF | HTTP client with user-controlled URL and no allowlist. |

## OWASP API Security Top 10 (2023)

| ID    | Risk | Key Detection Signal |
| ----- | ---- | -------------------- |
| API1  | Broken Object Level Auth (BOLA) | Resource by user-supplied ID without `AND owner_id = currentUser`. |
| API2  | Broken Authentication | JWT missing `exp`. Token not revoked on logout. Bearer in URL. |
| API3  | Broken Property Level Auth | Full ORM entity returned. No DTO projection. Mass assignment. |
| API4  | Unrestricted Resource Consumption | No server-enforced `limit`/`pageSize`. No throttle on heavy ops. |
| API5  | Broken Function Level Auth | Admin route reachable without role guard. |
| API6  | Unrestricted Business Flow | No verification on OTP/checkout/password-reset flows. |
| API8  | Security Misconfiguration | Stack trace in response. CORS `*` on authenticated routes. |
| API9  | Improper Inventory Management | Deprecated/undocumented endpoints still reachable. |
| API10 | Unsafe API Consumption | Third-party response used without schema validation. |

## Anti-Patterns

- **No IDOR**: Filter every resource query by `owner_id` or `tenantId` alongside the user-supplied ID.
- **No wildcard CORS**: Restrict to explicit, allowlisted origins — never `*` on authenticated routes.
- **No full entity return**: Always project to a DTO — never serialize raw ORM output to the API response.

## References

- [OWASP Web App — Full Detection Signals](references/owasp-web.md)
- [OWASP API — Full Detection Signals](references/owasp-api.md)