API Penetration Testing

APIs are the backbone of modern applications - and the most exploited attack surface. Our API penetration testing goes far beyond automated scanning to deliver a thorough, manual assessment of your REST, GraphQL, and gRPC endpoints against the OWASP API Security Top 10 2023. We focus on the vulnerabilities that automated tools consistently miss: Broken Object Level Authorization (BOLA) - the #1 API vulnerability - where a single misconfigured endpoint can expose every customer's data. We test for Broken Authentication, including JWT misconfigurations, token leakage, and OAuth flow manipulation. We probe for Broken Object Property Level Authorization (mass assignment), Server-Side Request Forgery (SSRF), and injection attacks specific to API contexts. Business logic testing is a core part of our methodology. We analyze how your API handles edge cases: rate limiting bypass, race conditions, privilege escalation through chained API calls, and payment or subscription logic manipulation. We test both authenticated and unauthenticated attack surfaces, including inter-service communication in microservices architectures. Our testing covers API versioning security, webhook validation, file upload handling, and pagination manipulation. For GraphQL APIs, we test for introspection exposure, query depth and complexity attacks, batching abuse, field-level authorization gaps, and subscription security via WebSockets. Every engagement begins with a free scoping call, and we provide a fixed-price proposal within 24 hours. Critical vulnerabilities discovered during testing are reported immediately - we never hold urgent findings for the final report.