testing-api-for-mass-assignment-vulnerability

Detect mass assignment vulnerabilities in API endpoints using Python scripts.

Updated Apr 26, 2026
One-click install
npx skills add https://github.com/Renzo-Tognella/UniversalThingsForMyAgents --skill testing-api-for-mass-assignment-vulnerability
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: testing-api-for-mass-assignment-vulnerability
Source: https://github.com/Renzo-Tognella/UniversalThingsForMyAgents/tree/main/skills/testing-api-for-mass-assignment-vulnerability
Command: npx skills add https://github.com/Renzo-Tognella/UniversalThingsForMyAgents --skill testing-api-for-mass-assignment-vulnerability

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires requests, json, and includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill detects and tests mass assignment vulnerabilities in APIs, helping ensure that users cannot modify object properties they should not have access to.

Core Features & Use Cases

  • Vulnerability Detection: Tests APIs for mass assignment vulnerabilities where clients can modify object properties through auto-binding.
  • Endpoint Testing: Identifies writable endpoints and verifies if all client-supplied properties are bound to the data model without an allowlist.
  • Privileged Fields: Checks if users can set privileged attributes such as role, permissions, pricing, and balance through update endpoints.
  • ORM Testing: Validates if server-side input validation restricts writeable properties per user role, particularly for ORMs that auto-bind request parameters to database models.
  • Use Case: Utilize this Skill to test APIs built with ORMs or RESTful services to ensure they are secure against mass assignment attacks, which can lead to role elevation or data manipulation.

Quick Start

Use the 'testing-api-for-mass-assignment-vulnerability' skill to scan the '/api/v1' endpoint for mass assignment vulnerabilities.

Frequently Asked Questions about testing-api-for-mass-assignment-vulnerability

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

FAQPage Schema
How do I test my API for mass assignment vulnerabilities?

To test an API for mass assignment vulnerabilities, you need to scan writeable endpoints and attempt to inject unfiltered properties into object models. This skill automates that process by manipulating request parameters to identify if privileged fields like role or balance can be modified.

What is a mass assignment vulnerability in an API?

Mass assignment vulnerabilities occur when an API auto-binds client-supplied request parameters directly to data model properties without an allowlist. This allows attackers to manipulate privileged fields like role, permissions, or balance through standard update endpoints.

Can I check if ORM auto-binding allows unauthorized property updates in my RESTful API?

Yes, you can check ORM auto-binding by sending crafted requests to your RESTful API endpoints to see if server-side input validation restricts writeable properties per user role. This skill specifically targets ORMs that auto-bind parameters to database models without filtering.

How do I detect if users can elevate their role through API endpoints?

You can detect role elevation risks by testing API update endpoints with injected privileged attributes such as role, permissions, and pricing. This skill identifies security issues by verifying if server-side validation restricts writeable properties per user role.

Do I need Python and the requests library to run mass assignment vulnerability tests?

Yes, you need Python and the requests library to execute the scripts that test for mass assignment vulnerabilities. The skill uses these dependencies to send HTTP requests and parse JSON responses from your target API endpoints.

What are the limitations of testing APIs for auto-binding security issues?

Testing auto-binding security issues requires identifying writable endpoints first, and results depend on the target API's specific ORM and data model structure. The tests focus on manipulating properties to find missing allowlists but may need endpoint-specific configuration for accurate detection.