api-auth-and-jwt-abuse

Identify weaknesses in API authentication and JWT implementations.

Updated Jun 11, 2026

Search Tags:#rate limiting #API security #JWT #API testing #token trust #header spoofing

Ready to run

npx skills add https://github.com/utsavthakur/agenticskills --skill api-auth-and-jwt-abuse-utsavthakur

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: api-auth-and-jwt-abuse
Source: https://github.com/utsavthakur/agenticskills/tree/main/api-auth-and-jwt-abuse
Command: npx skills add https://github.com/utsavthakur/agenticskills --skill api-auth-and-jwt-abuse-utsavthakur

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill identifies weaknesses in API authentication and JWT implementations, such as token trust boundaries, claim misuse, header spoofing, and rate-limit bypass.

Core Features & Use Cases

Token Trust Analysis: Inspects claims, issuer, audience, and reuse of tokens.
Quick Attack Pick: Identifies common attack patterns like alg:none and weak secrets.
Hidden Fields and Batch Abuse: Mass assignment and rate limit abuse identification.
Rate Limit Bypass: Detects bypass methods using headers and path variations.
Next Routing: Provides links to further resources for GraphQL, authentication bypass, and JWT depth.

Quick Start

Run the skill to test the security of your API's authentication and JWT implementation.

Frequently Asked Questions about api-auth-and-jwt-abuse

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

FAQPage Schema

How do I test my API for JWT vulnerabilities and weak token trust boundaries?▼

To test API authentication for JWT vulnerabilities, you analyze token trust boundaries, inspect claims for misuse, and check for common attack patterns like the alg:none bypass or weak signing secrets.

What is the best way to bypass API rate limiting using header spoofing?▼

Bypassing API rate limiting often involves header spoofing and path variations to manipulate request identity signals, allowing you to detect weaknesses in the rate-limiting mechanisms protecting the endpoint.

How does claim misuse affect API security when using bearer tokens?▼

Claim misuse compromises API security when bearer tokens are accepted without properly validating the issuer, audience, or token reuse, breaking the trust boundaries of the authentication implementation.

Can I detect mass assignment and batch abuse vulnerabilities in API testing?▼

Yes, you can detect mass assignment and batch abuse vulnerabilities during API testing by identifying hidden fields and analyzing how the API processes request identity signals and mass assignment parameters.

What are the common attack patterns to check for in JWT implementations?▼

Common attack patterns in JWT implementations include the alg:none attack, weak signing secrets, header spoofing, and insufficient validation of token trust boundaries during API authentication testing.