API penetration testing
API penetration testing
APIs fail differently from traditional web apps. The highest-impact issues are almost always authorization and business-logic flaws - not the injection bugs a scanner is tuned to find. Impactr tests REST and GraphQL APIs, with or without an OpenAPI spec, reasoning about object ownership and role boundaries across every endpoint.
The OWASP API Security Top 10, in practice
Broken Object Level Authorization (BOLA) tops the list for a reason - it's the single most common way an API leaks or exposes another user's data. Broken authentication, excessive data exposure from over-permissive serialization, and lack of resource-consumption limits round out the risks that matter most.
Business-logic abuse, not just broken endpoints
The riskiest API flaws are often intended functionality used the wrong way - a checkout flow that can be replayed, an invite endpoint that can be automated at scale, a discount code with no rate limit. These require reasoning about the flow, not scanning individual requests.
Testing without a spec
An OpenAPI or GraphQL schema speeds things up, but Impactr can also map an API's surface dynamically by observing real traffic and following the requests an authenticated client actually makes.
What Impactr does here
- Tests object- and function-level authorization across every role and tenant
- Parses OpenAPI/GraphQL schemas, or maps the surface dynamically without one
- Finds mass assignment and excessive data exposure, not just broken endpoints
- Chains authorization and business-logic findings into proven attack paths
See it work on your own application - Impactr investigates, chains, and proves impact with reproducible evidence.
Join the waitlistFAQ
Does API penetration testing require an OpenAPI or GraphQL schema?
No - a spec helps Impactr map the surface faster, but it can also discover endpoints dynamically from authenticated traffic when no spec is provided.
What's the single most important thing to test on an API?
Object-level authorization (BOLA) - confirming that every endpoint referencing an object checks that the requesting principal actually owns or may access it, not just that they're authenticated. It's the top category in the OWASP API Security Top 10 for a reason.
Can this test GraphQL APIs, or only REST?
Both. GraphQL introduces its own risks - introspection abuse, batching attacks, and depth/complexity-based denial of service - which Impactr tests for alongside standard REST authorization and injection issues.