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competition-web-runtime

Inspects web application runtime behavior, request flows, and routing in CTF sandbox challenges.

7|4|Updated Jun 22, 2026
Search Tags:#routing#web security#sandbox#ctf#request analysis#hmac#session forgery
One-click install
npx skills add https://github.com/dbx0/skills --skill competition-web-runtime-dbx0
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: competition-web-runtime
Source: https://github.com/dbx0/skills/tree/main/skills/web-appsec/initial-access/competition-web-runtime
Command: npx skills add https://github.com/dbx0/skills --skill competition-web-runtime-dbx0

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve? When solving CTF web, API, or SSR challenges, visible UI behavior often diverges from actual backend enforcement, and guessing from source code alone wastes time. This Skill provides a structured workflow for grounding analysis in real request flows, browser state, and sandbox routing before drawing conclusions. ## Core Features & Use Cases - Runtime Mapping: Identifies active hosts, proxies, containers, workers, cookies, storage, and service workers in the sandbox environment. - Request Flow Capture: Records exact request order, headers, and bodies to compare successful and failing paths instead of trusting UI gating. - Specialist Routing: Directs narrowly-scoped problems (SSRF, JWT confusion, race conditions, request smuggling, OAuth chains) to dedicated downstream skills. - Use Case: During a CTF web challenge, you capture one real end-to-end request flow, discover the admin cookie is HMAC-signed with the URL access token, and forge an administrator session to reach the flag endpoint. ## Quick Start Ask the agent to inspect the challenge site's real request flow and browser storage to explain why the frontend and backend behavior diverge.

Frequently Asked Questions about competition-web-runtime

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I debug a CTF web challenge where the UI and backend disagree?▼

Capture one real end-to-end request flow with exact hosts, paths, headers, and bodies, then compare successful and failing paths. Treat UI gating as a hint rather than proof of backend enforcement, and re-run the smallest flow with one variable changed.

How to find hidden routes in a web application during a CTF?▼

Inspect entry HTML, boot scripts, lazy chunks, runtime config, and route registration before trusting the visible UI. Verify hidden routes, alternate hostnames, and preview modes only after one legitimate flow is fully grounded.

Can a URL access token be reused to forge admin cookies?▼

Yes, when the server signs cookies with the same access token exposed in the URL and trusts client-side claims. The reference documents reproducing the HMAC signature with the known token and forging a payload like {"admin":true}.

When should I use this skill versus a specialized web exploitation skill?▼

Use this skill for general web runtime, routing, and request-flow analysis after the sandbox orchestrator is active. Narrow problems like SSRF, JWT claim confusion, race conditions, or request smuggling should route to their dedicated downstream skills.

What browser state should I inspect when analyzing web app behavior?▼

Inspect cookies, localStorage, sessionStorage, IndexedDB, Cache Storage, and service workers together with backend state. Record storage keys, feature flags, queue names, and worker identifiers that actually appear in the active flow.

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