common-owasp

common-owasp is a skill for Claude Code, Codex from HoangNguyen0403/agent-skills-standard. It costs 54 tokens per session (1,273 once invoked), scanned A, original, MIT.

A checklist based on the OWASP Top 10, a widely used list of common security risks in web apps, APIs, and mobile apps. It helps review code and security-sensitive changes for issues such as insecure access checks, overly broad CORS, and exposed secrets.

In plain words
What is it for?
Use it when reviewing web, API, or mobile code, checking pull requests, or auditing features that handle users, permissions, data, or credentials.
Why use it?
It prevents common security mistakes from being missed during code reviews and audits. It also makes findings easier to classify by application type and severity.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it when reviewing web, API, or mobile code, checking pull requests, or auditing features that handle users, permissions, data, or credentials.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hoangnguyen0403/agent-skills-standard/common-owasp
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add HoangNguyen0403/agent-skills-standard --skill common-owasp
Clone the repo
git clone --depth 1 https://github.com/HoangNguyen0403/agent-skills-standard

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for common-owasp

README.md
[![agentmods](https://agentmods.dev/badge/skills/hoangnguyen0403/agent-skills-standard/common-owasp/github.svg)](https://agentmods.dev/skills/hoangnguyen0403/agent-skills-standard/common-owasp)
Your own site
<a href="https://agentmods.dev/skills/hoangnguyen0403/agent-skills-standard/common-owasp"><img src="https://agentmods.dev/badge/skills/hoangnguyen0403/agent-skills-standard/common-owasp/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for common-owasp

Your own site · 80×15
<a href="https://agentmods.dev/skills/hoangnguyen0403/agent-skills-standard/common-owasp"><img src="https://agentmods.dev/badge/skills/hoangnguyen0403/agent-skills-standard/common-owasp.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,273 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 3 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Privilege Escalation · line 30
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • medium Excessive Agency · line 67
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
  • medium Rogue Agent · line 76
    Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.
    Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00054 $0.01273
Opus 5 $0.00027 $0.00636
Sonnet 5 $0.00011 $0.00255
Haiku 4.5 $0.00005 $0.00127

Measured 13d ago against content hash 58d12901cf8a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

common-owasp scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 13d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/common/common-owasp/SKILL.md · 100 lines

How it starts

The opening of the file, as written. The whole thing — 100 lines — stays where its author put it; the contents beside it link to each section on GitHub.

OWASP Top 10 Security Checklist

Priority: P0 (CRITICAL)

Always-Apply Rules

Apply these on every code write, not during dedicated security reviews:

  • No IDOR: Filter every resource query by owner_id or tenantId alongside any user-supplied ID. findById(params.id) without owner filter immediate P0.
  • No wildcard CORS: Restrict to explicit allowlisted origins — never Access-Control-Allow-Origin: * on authenticated routes.
  • No full entity return: Always project to DTO — never serialize raw ORM output to API response.
  • No plaintext secrets in mobile: Never store tokens in SharedPreferences/UserDefaults — use Keychain/Keystore.

Context-Specific Checklist

Activate when: writing security-sensitive features, reviewing PRs, or doing codebase audits.

Mark each item: ✅ not affected | ⚠️ needs review | 🔴 confirmed finding.

P0 finding caps Security score at 40/100.

Apply framework-specific security skills alongside this checklist. See references/owasp-web.md, references/owasp-api.md, and references/owasp-mobile.md for full detection signals.

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.

Read the full file on GitHub · 100 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 13d ago First seen · 100 lines · 54 tokens per session scan A 58d12901cf8a

Subscribe to this mod's changes

common-owasp is a skill published in the GitHub repository HoangNguyen0403/agent-skills-standard (565 stars, last pushed 3d ago), licensed MIT. It adds 54 tokens to every session and 1,273 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.