A process for authorized security testing of a live web application, including checks of login controls, sessions, access rights, request parameters, and business rules. Black-box testing uses limited internal knowledge; grey-box testing uses some access or credentials.

It is for planning and documenting web penetration tests with tools such as Burp Suite, OWASP ZAP, and curl.

It helps find exploitable flaws in a web application before attackers do, while keeping testing within the approved scope.

web-pentest — Cursor rule for Cursor by briiirussell

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.

Clone the repo

git clone --depth 1 https://github.com/briiirussell/cybersecurity-skills

Made for: Cursor.

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.

README.md

[![agentmods](https://agentmods.dev/badge/rules/briiirussell/cybersecurity-skills/web-pentest/github.svg)](https://agentmods.dev/rules/briiirussell/cybersecurity-skills/web-pentest)

Your own site

<a href="https://agentmods.dev/rules/briiirussell/cybersecurity-skills/web-pentest"><img src="https://agentmods.dev/badge/rules/briiirussell/cybersecurity-skills/web-pentest/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.

Your own site · 80×15

<a href="https://agentmods.dev/rules/briiirussell/cybersecurity-skills/web-pentest"><img src="https://agentmods.dev/badge/rules/briiirussell/cybersecurity-skills/web-pentest.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 114 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 2,747 The whole file, excluding the scripts and references it only reads on demand.

Security scan B 2 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00114	$0.02747
Opus 5	$0.00057	$0.01373
Sonnet 5	$0.00023	$0.00549
Haiku 4.5	$0.00011	$0.00275

Measured 10d ago against content hash 35f57a425d02, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade B, and why

web-pentest scanned grade B with 2 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 10d 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.

Reaches for credential filesmediumPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

- Backups / configs exposed — `/.git/`, `/.env`, `/backup.sql`, `/web.config`, `/server-status`, `/.aws/credentials`

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- HTTP headers — pull with `curl -I` and `curl -I -H "Origin: https://evil.com"`:

adapters/cursor/web-pentest.mdc · 202 lines

How it starts

The opening of the file, as written. The whole thing — 202 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Web Pentest — Live Web Application Testing

Structured black-box / grey-box penetration testing of a live web application against an authorized target. Pairs with recon (which maps the surface) and complements owasp-audit (which reads the source). Use recon first; use this once you have a target list and credentials (or guest access).

Authorization Check

Before touching the target, confirm:

Written authorization for this specific application (pentest engagement, bug bounty in-scope domain, CTF/lab, your own asset)
The application is currently in scope and live (not deprecated, not under maintenance freeze)
Test credentials provided (if grey-box), or guest access confirmed (if black-box)
Out-of-scope items documented — production user data, payment flows, social engineering, DoS

If anything is unclear, ask before proceeding. Never assume authorization.

Methodology

Follows the OWASP Web Security Testing Guide (WSTG) structure. Each phase produces evidence; document everything as you go.

Phase 1: Configuration & deployment

Goal: understand what's running and how it's exposed.

HTTP headers — pull with curl -I and curl -I -H "Origin: https://evil.com":
- Server, X-Powered-By revealing stack
- HSTS, CSP, X-Frame-Options, X-Content-Type-Options presence and values
- CORS — Access-Control-Allow-Origin reflection without an allow-list, Allow-Credentials: true paired with *
TLS — testssl.sh https://target or sslyze --regular target
Backups / configs exposed — /.git/, /.env, /backup.sql, /web.config, /server-status, /.aws/credentials
Default admin paths — /admin, /administrator, /manage, /console, /actuator/, /_debug/, /swagger, /graphql, /.well-known/
Robots.txt and sitemap.xml — often list non-indexed but accessible endpoints
Subdomain & host header testing — does the app behave differently when sent Host: internal.target.com?

Phase 2: Identity management

Goal: understand who can be created, how, and with what privileges.

Read the full file on GitHub · 202 lines

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.

10d ago First seen · 202 lines · 114 tokens per session scan B 35f57a425d02

Subscribe to this mod's changes

web-pentest is a cursor rule published in the GitHub repository briiirussell/cybersecurity-skills (384 stars, last pushed 3mo ago), licensed MIT. It adds 114 tokens to every session and 2,747 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it B with 2 findings (reaches for credential files, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Security Testing

web-pentest

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade B, and why

Reaches for credential filesmediumPrivilege escalation

Makes network callslowCapability

How it starts

Web Pentest — Live Web Application Testing

Authorization Check

Methodology

Phase 1: Configuration & deployment

Phase 2: Identity management

What this file has done since we first saw it

Other cursor rules, from other repositories

20-testing-generated-and-structure

fuzzing

testing-and-quality

smoke-monkey-tester

STAGE_S5_TEST_POINTS

testing