hunt-api-misconfig

Detect and validate API security misconfigurations across mass assignment, JWT, CORS, and HTTP verbs.

Updated Aug 27, 2026
One-click install
npx skills add https://github.com/AKasem1/claude-bug-bounty --skill hunt-api-misconfig
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: hunt-api-misconfig
Source: https://github.com/AKasem1/claude-bug-bounty/tree/main/skills/hunt-api-misconfig
Command: npx skills add https://github.com/AKasem1/claude-bug-bounty --skill hunt-api-misconfig

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

It helps security hunters quickly identify and validate high-impact API security misconfigurations that enable privilege escalation, account takeover, cross-origin data exposure, and other systemic auth/data-leak failures.

Core Features & Use Cases

  • Mass assignment & privilege escalation: Detects endpoints that blindly apply user-controlled fields (for example, turning a normal user into admin by submitting role or verification flags).
  • JWT weaknesses & token manipulation: Finds and tests common JWT flaws such as alg=none acceptance, algorithm confusion (e.g., RS256 vs HS256), and token/header manipulation vectors.
  • Prototype pollution, CORS, and HTTP verb attacks: Identifies JSON/object merge pollution paths, CORS credentialed misconfigurations, and HTTP method tampering that can bypass intended protections.

Use case example: A target application’s API returns “extra” fields in responses and accepts attacker-injected JWT claims; use this Skill to validate misconfiguration impact and produce a structured vulnerability path with evidence.

Quick Start

Use the hunt-api-misconfig skill against the target API by requesting a focused misconfiguration report with mass-assignment tests, JWT validation checks, and CORS/verb-tampering evidence.

Frequently Asked Questions about hunt-api-misconfig

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

FAQPage Schema
How do I detect API security misconfigurations like mass assignment and CORS bypasses?▼

To detect API security misconfigurations, you test endpoints for mass assignment, CORS bypasses, and HTTP verb tampering by manipulating attacker-controlled request bodies, origins, and methods to subvert authentication and authorization controls.

How does JWT algorithm confusion happen and how can I test for it?▼

JWT algorithm confusion happens when a token switches from RS256 to HS256, allowing attackers to sign tokens with a public key. You test for this by manipulating JWT headers and claims to see if the API accepts forged tokens.

What is prototype pollution in APIs and when do I need to test for it?▼

Prototype pollution in APIs occurs when JSON object merging injects malicious properties into base prototypes. You need to test for it when APIs process and merge attacker-controlled JSON payloads, which can subvert application logic.

How do I validate privilege escalation via mass assignment vulnerabilities?▼

To validate privilege escalation via mass assignment, submit attacker-controlled fields like role or verification flags in the request body and observe if the API blindly applies them to elevate a normal user to an administrator.

Can I use this approach to find cross-origin data exposure through CORS misconfigurations?▼

Yes, you can find cross-origin data exposure by testing CORS credentialed misconfigurations, sending spoofed attacker-controlled origins in headers to see if the API subverts cross-origin access protections and leaks data.