skills.rest
securityfortech
securityfortechOFFICIAL
Explore all skills by this author →
WebsiteGitHub

jwt-misconfig

Identify and exploit JWT misconfigurations including algorithm confusion and weak HMAC secrets.

6|1|Updated Mar 9, 2026
Search Tags:#authentication#jwt#web security#vulnerability testing#api security#misconfiguration
One-click install
npx skills add https://github.com/securityfortech/hacking-skills --skill jwt-misconfig
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: jwt-misconfig
Source: https://github.com/securityfortech/hacking-skills/tree/main/skills/web/auth/jwt-misconfig
Command: npx skills add https://github.com/securityfortech/hacking-skills --skill jwt-misconfig

SYSTEM DOCUMENTATION & REQUIREMENTS

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

What problem does it solve?

This Skill helps identify and exploit common misconfigurations in JSON Web Token (JWT) based authentication systems, preventing unauthorized access and privilege escalation.

Core Features & Use Cases

  • Detects Algorithmic Confusion: Identifies scenarios where servers incorrectly handle different JWT signing algorithms (e.g., RS256 vs. HS256).
  • Exploits alg:none: Leverages JWT libraries that improperly accept tokens with no signature.
  • Cracks Weak Secrets: Attempts to brute-force weak or dictionary-based HMAC secrets.
  • Identifies kid Parameter Vulnerabilities: Tests for path traversal or SQL injection via the Key ID parameter.
  • Use Case: When encountering an Authorization: Bearer <token> header, this skill will attempt to forge a valid token with elevated privileges by exploiting a weak secret or algorithm confusion.

Quick Start

Use the jwt-misconfig skill to test the provided JWT token for common vulnerabilities.

Frequently Asked Questions about jwt-misconfig

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

FAQPage Schema
How do I exploit JWT algorithm confusion vulnerabilities in web applications?▼

To exploit JWT algorithm confusion, the skill manipulates token headers to mismatch RS256 and HS256 signing algorithms, forging valid tokens with elevated privileges when servers improperly handle asymmetric and symmetric keys.

What is the best way to test for alg:none bypass and weak HMAC secrets in JWT authentication?▼

Testing for alg:none bypass and weak HMAC secrets involves stripping token signatures and brute-forcing dictionary-based keys using hashcat to forge unauthorized JSON Web Token access.

Can I use jwt_tool and hashcat to test API security misconfigurations?▼

Yes, you can use jwt_tool and hashcat to analyze token structures, crack weak HMAC secrets, and identify API security misconfigurations in Authorization Bearer headers.

How do I perform kid parameter injection to exploit JWT vulnerabilities?▼

To perform kid parameter injection, the skill tests the Key ID header for path traversal and SQL injection flaws, manipulating key retrieval paths to forge valid authentication tokens.

When should I test JWT misconfigurations for SSO and API authorization systems?▼

You should test JWT misconfigurations for SSO and API authorization systems whenever you encounter Bearer token authentication, preventing unauthorized access and privilege escalation through weak secrets or algorithm flaws.

Related Skills

Explore More Software Engineering Skills→
klu-devklu-dev
2

springboot-security

Secure Java Spring Boot applications with JWT, role-based access, and OWASP dependency scanning.

Community
Intermediate
Muskan492Muskan492

auth-skill

Implement user signup, signin, password hashing, and JWT token generation.

Community
Advanced
jokken79jokken79
1

Burp Suite Web Application Testing

Intercept, modify, and analyze HTTP traffic to identify web application vulnerabilities.

Community
Advanced
Q16GQ16G
83

api-token-sec

Detect API token, CORS, and JWT security weaknesses in REST APIs.

Community
Intermediate