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OWASP API Top 10

API Penetration Testing

Comprehensive security testing of REST, GraphQL, SOAP, and gRPC APIs. We identify authentication flaws, data exposure risks, and business logic vulnerabilities in your API infrastructure.

Testing Scope

Complete API Security Assessment

Our API penetration testing covers all aspects of API security following OWASP API Security Top 10.

Authentication & Authorization

  • Broken authentication
  • JWT security testing
  • OAuth implementation
  • API key management
  • Role-based access control

Data Exposure

  • Excessive data exposure
  • Mass assignment
  • Sensitive data in responses
  • Error message disclosure
  • Information leakage

API Logic & Rate Limiting

  • Rate limiting bypass
  • Resource enumeration
  • Business logic flaws
  • Injection attacks
  • Server-side request forgery

API pentest procurement guide

Scope an API test that covers the real authorization boundary

A useful API penetration test is defined by business objects, identities and trust boundaries—not only by endpoint count. During scoping, nCrypt maps user roles, tenant boundaries, partner integrations, machine identities and sensitive workflows so testing can exercise the authorization decisions that create the highest business impact. Active testing starts only after the customer approves the target list, test accounts, testing window and rules of engagement.

Identity and session paths

We test login, token issue and refresh, logout, password reset, MFA, API keys, OAuth/OIDC flows and service-to-service credentials. The objective is to determine whether a lower-trust identity can obtain or retain access beyond its intended role.

Object and function authorization

Testing covers BOLA/IDOR, broken function-level authorization, tenant isolation, administrative actions and workflow state changes. We use approved accounts representing different roles and tenants so cross-account results are reproducible.

Input, resource and business logic

We assess injection, mass assignment, unsafe file or URL handling, GraphQL query controls, pagination, rate limits and abuse of multi-step transactions. Testing is adapted to the API design rather than reduced to an automated OWASP checklist.

Integrations and exposed inventory

The scope can include public, mobile-backend, partner and webhook endpoints; REST, GraphQL, SOAP and gRPC interfaces; and documented or discovered versions. Undocumented endpoints are reported as attack-surface findings, not silently added to active scope.

What we need before kickoff

  • An OpenAPI/Swagger, Postman, GraphQL or equivalent interface definition where available.
  • Test accounts for each approved role and at least two tenants when tenant isolation is in scope.
  • A target environment, source-IP allowlisting process, emergency contact and agreed testing window.
  • A data-handling decision for any endpoint that may return personal, payment or production information.

What you receive

  • Executive and technical reports with CVSS scoring, affected endpoints and business impact.
  • Masked request/response evidence and reproducible steps for every confirmed finding.
  • A prioritized remediation register covering code, gateway and identity-control fixes.
  • A verification report after approved fixes are deployed and retested.

Boundaries and assumptions

  • No destructive, denial-of-service or unapproved production-data extraction testing.
  • Third-party APIs require written authorization from the party that owns the target.
  • Source-code review, cloud control-plane review and mobile binary testing are separate unless included in scope.
  • Endpoint counts guide effort, but identity roles and business workflows usually drive the final test duration.

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