hunt-fastapi

What problem does it solve?

FastAPI's unique architecture including dependency injection for authorization, Pydantic for request validation, auto-generated OpenAPI schemas, and ASGI middleware creates specialized attack surfaces that generic web vulnerability scanners often miss, leaving critical application flaws undetected during security assessments.

Core Features & Use Cases

• OpenAPI Schema Mining: Discover hidden, undocumented endpoints and internal API routes exposed in auto-generated OpenAPI schemas for FastAPI applications.
• FastAPI-Specific Auth Testing: Identify authorization gaps in dependency injection (Depends) configurations, including endpoints that skip authentication checks entirely or have misconfigured dependency overrides.
• Pydantic & ASGI Exploitation: Test for type coercion flaws, extra field injection, and proxy header/IP spoofing via misconfigured ASGI middleware and TrustedHost settings.
• Use Case: When conducting a penetration test of a FastAPI-powered customer portal, use this skill to systematically find hidden admin endpoints in the OpenAPI schema, test for auth bypasses in DI-protected routes, and check for Pydantic coercion flaws that allow attackers to set admin privileges via string inputs.

Quick Start

Use the hunt-fastapi skill to assess the target FastAPI application for dependency injection authorization gaps, hidden OpenAPI endpoints, and Pydantic validation flaws.