API Penetration Testing Services
Expert-led API security testing focused on identity, authorization, data exposure and business-logic abuse.
Assessment coverage
- Auth & rate limit tests
- Schema fuzzing & input validation
- Broken Object Level Auth (BOLA/IDOR)
- Mass assignment & parameter tampering
- Exploit POCs & regression checks
How the assessment works
We assess APIs across discovery, unauthenticated endpoints, authenticated flows, and business logic. Testing modes:
Black-box: External API discovery, endpoint enumeration, fuzzing and unauthenticated attack paths. Focus on public APIs, rate limit bypass, and injection via request payloads.
Gray-box: Tests with valid credentials, API keys or tokens to exercise user-scoped functionality. Focus on BOLA/IDOR, privilege escalation via parameter tampering, and chaining of API calls to reach sensitive state changes.
White-box: Schema and source review, static analysis of handlers/controllers, and dependency checks. Focus on insecure deserialization, unsafe use of user data, and code-level remediation guidance.
We also validate authentication flows (JWT/OAuth), token handling, CORS, and error/message leakage.
Report and remediation deliverables
- API call map and endpoint inventory
- Exploit PoCs and replayable curl/postman collections
- Schema validation report and fuzzing coverage
- Remediation steps with code pointers (if white-box)
- CI artifacts (SARIF/JSON) for pipeline enforcement
OWASP API Security Top 10:2023
APIs fail differently to browser based web apps. Traditional web testing assumes a browser is rendering pages and enforcing some rules for you along the way, an API has no browser in the loop, so every authorization check has to be enforced correctly by the backend itself, every single time, for every object and every field. That is why OWASP maintains a separate list specifically for APIs, and why authorization failures dominate the top of it rather than the injection and configuration issues that lead the general web list.
