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    API Security Testing

    Comprehensive guide to testing REST and GraphQL API security. Learn how to identify authorization bypass, data exposure, and injection vulnerabilities in API endpoints.

    API Security is Critical

    APIs are the backbone of modern applications and a primary attack vector. AI-generated APIs often have broken authorization, excessive data exposure, or missing security controls. Thorough API security testing is essential before launch.

    API Security Testing Checklist

    Follow these 10 steps to thoroughly test your API security. Critical items should be tested on every API endpoint before production deployment.

    Step 1

    API authentication testing

    Critical

    Test authentication mechanisms including JWT validation, API key handling, and OAuth implementation.

    Step 2

    Authorization testing

    Critical

    Verify that API endpoints enforce proper authorization and users cannot access unauthorized resources.

    Step 3

    Input validation testing

    Critical

    Test all API parameters for injection vulnerabilities, type confusion, and input validation bypass.

    Step 4

    Rate limiting verification

    Critical

    Test that rate limiting is properly implemented to prevent brute force attacks and API abuse.

    Step 5

    Sensitive data exposure

    Critical

    Review API responses for excessive data exposure, PII leakage, and sensitive information in error messages.

    Step 6

    Mass assignment testing

    Test for mass assignment vulnerabilities where users can modify unauthorized fields through API parameters.

    Step 7

    API versioning security

    Verify that older API versions are properly deprecated and do not expose security vulnerabilities.

    Step 8

    CORS configuration review

    Test CORS policies to ensure only authorized origins can access your API endpoints.

    Step 9

    GraphQL security testing

    Test GraphQL endpoints for query depth limits, introspection exposure, and authorization bypass.

    Step 10

    API documentation testing

    Verify that API documentation does not expose internal endpoints or sensitive implementation details.

    Common API Vulnerabilities

    Broken Object Level Authorization

    Critical

    Users can access objects they should not have permission to view or modify by changing IDs in API requests.

    Excessive Data Exposure

    High

    API returns more data than needed, exposing PII or sensitive information that clients should not receive.

    Missing Rate Limiting

    High

    API endpoints lack rate limiting, allowing brute force attacks, credential stuffing, or resource exhaustion.

    Mass Assignment

    High

    API allows modification of object properties that should be restricted, leading to privilege escalation.

    Related Resources

    Penetration Testing Guide

    Complete penetration testing methodology

    Automated Security Testing

    Automate API security testing in CI/CD

    Manual Security Testing

    Manual testing techniques for complex API logic

    Common Security Flaws

    Most common vulnerabilities in AI-generated code

    Automated API Security Testing

    VibeEval includes comprehensive API security testing that automatically detects authorization issues, data exposure, and injection vulnerabilities in your endpoints.

    Start API Security Scan