Purpose
When this assessment fits
Modern applications rely heavily on APIs to handle customer data, process transactions, manage account actions, and facilitate mobile app traffic, partner integrations, or internal business workflows. Because APIs often expose the core logic and data of an application directly, they are high-value targets for attackers. This specialized assessment is crucial for organizations that need to ensure their APIs are not inadvertently leaking sensitive data, failing to enforce proper authorization boundaries, or susceptible to abuse that could disrupt business operations.
What we review
- REST API endpoints
- GraphQL endpoints
- Authentication and token flows
- JWT handling
- Object-level authorization (BOLA/IDOR)
- Function-level authorization
- Role-based API access
- Data exposure in responses
- Mass assignment risk
- Rate limit and abuse controls
- CORS configuration
- Webhook security
- API documentation exposure
Common risks we help identify
- →Users accessing another user’s records by changing object identifiers (BOLA)
- →Missing authorization checks on sensitive API actions
- →Excessive data returned in API responses (Mass Exposure)
- →Weak or long-lived tokens allowing session hijacking
- →Unsafe CORS policies permitting unauthorized cross-origin requests
- →Lack of rate limits on sensitive actions leading to brute-force or DoS
- →Internal or debug endpoints exposed publicly
- →Webhooks that trust unverified requests
Business value
- Secure Third-Party Integrations: Ensure that partner APIs and webhooks do not introduce vulnerabilities into your ecosystem.
- Protect Mobile Application Backends: Safeguard the APIs that power your mobile applications from unauthorized access and data scraping.
- Prevent Mass Data Exfiltration: Identify and fix excessive data exposure vulnerabilities that could lead to large-scale data breaches.
- Ensure Reliable API Performance: Validate rate limiting and abuse controls to prevent denial-of-service attacks and ensure consistent service availability.
Methodology coverage
Our API Security Testing methodology goes beyond basic vulnerability scanning by focusing heavily on business logic and authorization flaws. We begin by thoroughly understanding the API's intended functionality and architecture. Our engineers then manually test for complex vulnerabilities such as Broken Object Level Authorization (BOLA), mass assignment, and excessive data exposure. We analyze token generation, validation, and lifecycle management, ensuring that authentication mechanisms are robust. The result is a detailed, actionable report that clearly outlines the risks and provides precise remediation steps for your development team.
What we need from you
- →API base URLs
- →API documentation (Swagger, Postman collections, GraphQL schema) if available
- →Test credentials for each role
- →Example workflows
- →Authentication method details
- →Scope boundaries and restrictions
Frequently asked questions
Can you test undocumented APIs?
Yes. API discovery can be performed when authorized, but provided documentation significantly improves coverage, accuracy, and testing efficiency.
Do you test GraphQL?
Yes. GraphQL testing includes checking for schema exposure, authorization gaps, query depth/complexity limits, excessive data exposure, and role boundary enforcement.
Do you test mobile app APIs?
Yes. Mobile APIs are frequently assessed either as part of a dedicated API Security Testing engagement or integrated into a comprehensive Mobile Application Security Assessment.
