API Penetration Testing

We test for all OWASP API Security Top 10 vulnerabilities including broken object level authorization, broken user authentication, excessive data exposure, lack of resources and rate limiting, broken function level authorization, mass assignment, security misconfiguration, injection, improper assets management, and insufficient logging. This industry-standard framework ensures comprehensive coverage of the most critical API security issues.

We thoroughly test API authentication mechanisms including API keys, OAuth 2.0, JWT tokens, and custom authentication schemes. We look for token manipulation vulnerabilities, authentication bypass techniques, weak credential storage, and session management issues. We also test authorization logic to ensure users can only access data and functionality appropriate to their permission level, preventing privilege escalation and unauthorized data access.

BOLA vulnerabilities allow attackers to access data belonging to other users by manipulating object identifiers. We systematically test every endpoint that accepts IDs or references, attempting to access resources belonging to other users or organizations. This is consistently the #1 API security risk and requires thorough manual testing that automated tools often miss. We help you implement proper authorization checks to protect sensitive data.

Many APIs expose more information than needed, relying on client applications to filter sensitive data. We analyze API responses to identify excessive data exposure - personally identifiable information, internal system details, or business data that shouldn't be accessible. We examine whether APIs leak information about system architecture, database structures, or other technical details that could aid attackers.

We test whether your APIs properly limit request rates to prevent abuse, denial of service, and resource exhaustion. We attempt brute force attacks, credential stuffing, data scraping, and other abuse scenarios to verify that rate limiting and throttling mechanisms are properly implemented. We also test for business logic flaws that could allow attackers to bypass payment systems or abuse functionality through automated requests.

GraphQL APIs have unique security considerations including query depth and complexity attacks, introspection exposure, batching attacks, and field-level authorization issues. We test for GraphQL-specific vulnerabilities that could allow denial of service through expensive queries, information disclosure through introspection, and unauthorized data access through nested queries. Our specialized expertise ensures comprehensive coverage beyond generic API testing.

We examine your API documentation for information leakage, test for undocumented endpoints that may have weaker security, and verify that security headers and CORS policies are properly configured. We check for improper assets management - shadow APIs, old versions, and deprecated endpoints that may still be accessible. We also test whether verbose error messages expose system information that could help attackers.