access-mass-assignment

Inject unauthorized fields into API request payloads to detect mass assignment vulnerabilities.

Updated Jul 30, 2026

Search Tags:#api-security #security-audit #pentest #privilege-escalation #vulnerability-scanning #mass-assignment

Ready to run

npx skills add https://github.com/salmanabdurrahman/pi-pentest-agent --skill access-mass-assignment

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: access-mass-assignment
Source: https://github.com/salmanabdurrahman/pi-pentest-agent/tree/main/skills/access-mass-assignment
Command: npx skills add https://github.com/salmanabdurrahman/pi-pentest-agent --skill access-mass-assignment

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This skill identifies critical API vulnerabilities where unauthorized users can modify internal or administrative fields by injecting unexpected properties into request payloads.

Core Features & Use Cases

Field Surface Mapping: Automatically compares request and response shapes to identify hidden or server-managed fields.
Injection Testing: Systematically tests body, query, nested, and array parameters to detect improper field binding.
Use Case: Use this during a security audit to verify that a standard user profile update endpoint does not allow a user to escalate their own privileges by injecting an is_admin field into the JSON request.

Quick Start

Use the access-mass-assignment skill to audit the user profile update endpoint for potential over-posting vulnerabilities.

Frequently Asked Questions about access-mass-assignment

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

FAQPage Schema

What is mass assignment vulnerability testing in API security?▼

Mass assignment vulnerability testing injects unauthorized fields into request payloads to detect improper field binding. It identifies critical API vulnerabilities where unauthorized users can modify internal or administrative fields by injecting unexpected properties into request payloads.

How do I audit API endpoints for over-posting vulnerabilities?▼

To audit API endpoints for over-posting vulnerabilities, map request and response shapes to identify hidden fields, then systematically inject unauthorized properties into body, query, nested, and array parameters to detect improper field binding.

Does mass assignment testing work with nested serializers and JSON binding?▼

Yes, mass assignment testing targets web applications using nested serializers, JSON binding, or query parameter parsing. It systematically tests these parsing mechanisms to ensure strict field-level authorization across all input vectors.

What do I need to perform safe API security probing for privilege escalation?▼

Safe API security probing for privilege escalation requires a defined test scope, authorized test accounts, and a valid authorization cache. These prerequisites ensure safe, evidence-backed security probing during the vulnerability audit.

When should I use automated vulnerability scanning for mass assignment?▼

Use automated vulnerability scanning for mass assignment during a security audit to verify endpoints do not allow users to escalate privileges by injecting administrative fields like is_admin into JSON requests.