API Security Testing
API penetration testing for REST and GraphQL backends. Deep testing of authorization, injection, rate limiting, and data exposure — the OWASP API Security Top 10 and beyond.
Overview
APIs are where the real data lives, and they are frequently under-tested. Broken object-level authorization (BOLA) and broken function-level authorization remain the most damaging and most common API vulnerabilities — and they are invisible to most automated tooling.
I test your API the way an attacker with a valid account would: enumerating objects, swapping identifiers, abusing under-protected endpoints, and probing every trust boundary between services.
What you walk away with
- Full authorization matrix tested across roles and tenants
- Reproducible requests for every confirmed finding
- Guidance mapped to the OWASP API Security Top 10
- Retest included once fixes are deployed
What gets tested
A representative view of the attack surface I probe by hand during this engagement.
Broken Object-Level Authorization
The #1 API risk — accessing other tenants' or users' data by manipulating IDs.
Broken Function-Level Authorization
Calling admin or privileged endpoints from lower-privileged accounts.
Mass Assignment
Overwriting protected fields like roles, flags, or ownership via request bodies.
Injection & Data Exposure
Injection across parameters plus excessive data returned in API responses.
GraphQL-Specific Abuse
Introspection, deeply nested queries, batching attacks, and resolver-level authorization.
Rate Limiting & Abuse
Resource exhaustion, enumeration, and missing throttling on sensitive actions.
API Security Testing — common questions
Yes. GraphQL introduces its own risks — introspection exposure, query depth abuse, batching, and resolver-level authorization gaps — and each is covered as part of a GraphQL engagement.
Absolutely. APIs are tested directly using documentation, an OpenAPI/GraphQL schema, or a Postman collection, along with test credentials for each role.
You provide test accounts and I generate tokens through your normal auth flow, testing how those tokens are issued, scoped, and validated across endpoints.
Other services
Ready to find your vulnerabilities before attackers do?
Book a security assessment and get a clear, prioritized picture of your application's real risk. No obligation, no automated-scan fluff.