API Vulnerability Assessment and Penetration Testing

We test all types of APIs including REST APIs, GraphQL APIs, SOAP/XML web services, gRPC APIs, WebSocket APIs, and webhook implementations. Our testing covers both public-facing APIs and internal/microservice APIs. We work with any API regardless of the technology stack or framework used.

BOLA (Broken Object Level Authorization), also known as IDOR, occurs when an API doesn't properly verify that the requesting user has permission to access a specific object. For example, changing /api/users/123 to /api/users/456 to access another user's data. It's #1 because it's extremely common, easy to exploit, and can lead to massive data breaches.

GraphQL has unique security concerns: introspection queries can expose the entire schema, nested queries can cause DoS through complexity attacks, batching enables brute-force attacks, and field-level authorization is often overlooked. We test for GraphQL-specific vulnerabilities including query depth attacks, alias-based DoS, and mutations without proper authorization.

Documentation (OpenAPI/Swagger, Postman collections) helps accelerate testing, but it's not required. We can discover API endpoints through traffic analysis, mobile app reverse engineering, or web application inspection. We often find undocumented endpoints that aren't in official documentation but are still accessible.

Timeline depends on API complexity and scope. A typical REST API assessment with 20-50 endpoints takes 1-2 weeks. Complex APIs with multiple authentication methods, extensive business logic, or GraphQL take 2-3 weeks. Large microservice architectures may take 4+ weeks. We provide detailed scoping during initial consultation.

We use industry-leading tools including Burp Suite with API-specific extensions, Postman for API interaction, OWASP ZAP for automated scanning, custom Python/Go scripts for fuzzing, GraphQL-specific tools like InQL and GraphQL Voyager, and specialized tools for JWT testing and rate limit analysis.

Yes, we have extensive experience testing OAuth 2.0 flows (Authorization Code, PKCE, Client Credentials), OpenID Connect, JWT-based authentication, API key schemes, and custom authentication mechanisms. We test for token leakage, improper token validation, scope bypass, and other authentication vulnerabilities.

You receive: Executive Summary, Technical Report with CVSS scores and proof-of-concept requests, Remediation Guide with code examples, Postman/Swagger collection of all tested endpoints, API inventory with risk ratings, and compliance mapping. Plus a report walkthrough session and free retesting after fixes.

Yes, we test both external-facing and internal APIs. Internal APIs often lack proper authentication assuming they're "internal only", but attackers who breach the perimeter can exploit these. We can work with VPN access, test environments, or API gateways to assess your internal API security.

Cost depends on: number of endpoints, API complexity (REST vs GraphQL vs gRPC), authentication mechanisms, need for business logic testing, and compliance requirements. A basic REST API assessment starts at one price point, while comprehensive testing of complex microservice architectures costs more. Contact us for a free consultation and accurate quote.

Not strictly, but it changes what the time buys. With a specification, a Postman collection or a capture of real traffic, the work starts on testing. Without one, the first part of the engagement goes to discovering what exists, and anything undocumented that we fail to find stays untested.

Because broken object-level authorization is the first item in the OWASP API Top 10 and it cannot be demonstrated with one account. The test is whether user A can read or change user B data, and that needs a real B to point at.

A gateway limits how fast something can be called; it does not decide whether the caller should have been allowed at all. Authorization, business logic and the data in a response sit behind it and are untouched by it. Part of the test therefore runs with our addresses allowed through, so what is measured is the API rather than the gateway in front of it.

Yes, with the hours and the limits agreed beforehand. Two parts need care: testing resource limits means sending traffic that looks abusive, and any operation that writes needs an agreement about what may be created and how it is cleaned up afterwards.