offensive-jwt skillA
offensive-jwt is agent-read markdown (skill) from snailsploit/claude-red: JWT attack methodology for penetration testers. Covers algorithm confusion (alg:none, RS256→HS256), weak HMAC secret brute force, kid parameter injection (SQLi, path traversal), jku/x5u/jwk header injection, JWKS cache poisoning, JWS/JWE confusion, timing attacks, and mobile JWT storage extraction. Use when testing JWT-based authentication, hunting auth bypass via token manipulation, or evaluating JWT implementation security in web or mobile apps..
Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.
What the file says
## Overview Comprehensive JWT attack checklist for offensive security engagements. Follow steps in order; apply each technique to the current target context and track which items have been completed. ## Quick Reference: Misconfigurations to Check - Algorithm set to `none` — signature verification bypassed entirely - Algorithm switching between `RSA` and `HMAC` (confusion attack) - Weak or guessable HMAC secret (brute-forceable) - `kid`, `jku`, `jwk`, `x5u` header parameters accepted without validation - Expired or tampered tokens accepted by server - Sensitive data stored unencrypted in payload Useful tool: [JWT Tool](https://github.com/ticarpi/jwt_tool) ## Mechanisms JWTs (RFC 7519) consist of three Base64URL-encoded parts: `header.payload.signature`. **Signing algorithms:** | Algorithm | Type | Notes | |-----------|------|-------| | HS256/384/512 | Symmetric HMAC | Shared secret; confusion target | | RS256/384/512 | Asymmetric RSA | Public key can be misused as HMAC secret | | ES256/384/512 | Asymmetric ECDSA | | | PS256/384/512 | RSASSA-PSS | | | EdDSA (Ed25519/Ed448) | Asymmetric | | | none | Unsigned | Critically insecure | **Additional pitfalls:** …
Read the whole file at its exact version.
How to install
mdr add snailsploit/claude-red/offensive-jwt@git:20260506.70e0c89mdr add snailsploit/claude-red/offensive-jwt@sha256:f4062ca66c1241fbPin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.
[](https://markdownregistry.com/a/art_bfxckqf7uyf4dzc6)
1 badge views in 30 days
Versions
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (10861 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
snailsploit/claude-red · 6,831 stars · license MIT · pushed 2026-09-19 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_bfxckqf7uyf4dzc6 GET https://markdownregistry.com/api/v1/resolve?ref=snailsploit/claude-red/offensive-jwt GET https://markdownregistry.com/api/v1/blob/f4062ca66c1241fbeb772e1671d0d86d3683e27f33744fee6723b13a934a3fb9
Your agent does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
More from snailsploit/claude-red
Every file in snailsploit/claude-red