Conducting API Security Testing

When to Use

• Testing API endpoints for authorization flaws, injection vulnerabilities, and business logic bypasses
• Assessing the security of microservices architecture where APIs are the primary communication method
• Validating that API gateway protections (rate limiting, authentication, input validation) are properly enforced
• Testing third-party API integrations for data exposure and insecure configurations
• Evaluating GraphQL APIs for introspection disclosure, query complexity attacks, and authorization bypasses

Do not use against APIs without written authorization, for load testing or denial-of-service testing unless explicitly scoped, or for testing production APIs that process real financial transactions without safeguards.

Prerequisites

• API documentation (OpenAPI/Swagger, GraphQL schema, Postman collection) or application access to reverse-engineer the API
• Burp Suite Professional configured to intercept API traffic with JSON/XML content type handling
• Postman or Insomnia for organizing and replaying API requests across different authentication contexts
• Valid API tokens or credentials at multiple privilege levels (unauthenticated, standard user, admin)
• Target API base URL and version information