Every API Endpoint. Every Authorization Path. Every Injection Vector.
Modern applications expose hundreds of API endpoints. We test every one — OWASP API Security Top 10, broken authentication, BOLA/BFLA, and injection across REST, GraphQL, and gRPC.
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Modern applications are APIs. Your web application is an API client. Your mobile app is an API client. Your AI agents call APIs. Your third-party integrations consume your APIs.
API security testing is where the real attack surface lives — and where automated scanning falls furthest short of reality.
The BOLA Problem
Broken Object Level Authorization (BOLA) — formerly known as IDOR — is consistently the most prevalent finding in API security assessments. It’s also the hardest vulnerability for automated tools to detect.
BOLA means: can user A access user B’s resources by guessing or enumerating object identifiers? In an API, this might look like changing GET /api/users/1234/profile to GET /api/users/1235/profile and receiving another user’s data.
Automated scanners cannot test BOLA without understanding your application’s authorization model. Only a human researcher who understands which resources should be isolated between users can systematically test whether that isolation actually exists.
The QA Gap in API Security
Your API integration tests are designed to verify that your application works correctly. They test happy paths, expected inputs, and normal user behavior. They are not designed to test what happens when an adversary sends unexpected inputs, manipulates object identifiers, or attempts to call privileged functions with a standard user token.
BOLA testing requires two accounts and deliberate adversarial intent. Your integration tests use one account and test expected behavior. BFLA testing requires testing function-level permissions that your integration tests typically assume are correct. Injection testing requires adversarial payloads that your integration test suite would never generate.
This is not a failure of your QA team — it is a scope boundary. API security testing extends what your integration tests cover by introducing adversarial test cases, multi-account authorization testing, and injection sweeps that sit outside the charter of functional quality assurance.
GraphQL-Specific Risks
GraphQL introduces security considerations that REST APIs don’t share. Our GraphQL testing covers:
- Introspection exposure — schema discovery by adversaries
- Batching attacks — multiple operations in a single request to bypass rate limiting
- Field-level authorization — can users query fields they shouldn’t access?
- Injection — GraphQL injection targeting underlying resolvers
- Deeply nested queries — resource exhaustion via complexity attacks
LLM API Endpoints
If your API exposes LLM-powered endpoints that accept user-controlled prompts, those endpoints require additional testing beyond standard API security assessment — specifically prompt injection testing against the model layer. We include basic LLM endpoint injection testing in our API Security Testing scope, with a recommendation to combine with LLM Penetration Testing for comprehensive OWASP LLM Top 10 coverage.
Engagement Phases
API Discovery
Complete API inventory, endpoint enumeration, schema discovery (including undocumented endpoints), authentication mechanism analysis.
Authentication & Authorization Testing
Authentication bypass attempts, BOLA testing (can user A access user B's resources?), BFLA testing (can standard users perform privileged operations?), JWT analysis.
Business Logic & Injection
Business logic flaw analysis, injection testing (SQL, NoSQL, command, GraphQL injection), rate limiting bypass, mass assignment testing.
Reporting
OWASP API Security Top 10 compliance report, full findings with CVSS scores, API inventory document, remediation guidance.
Deliverables
Before & After
| Metric | Before | After |
|---|---|---|
| Endpoint Coverage | Documented endpoints only | Full inventory including undocumented endpoints |
| Authorization Testing | Authenticated vs unauthenticated access only | BOLA, BFLA, privilege escalation paths |
| AI Endpoint Coverage | LLM API endpoints not tested for prompt injection | All AI/LLM API endpoints tested for injection |
Tools We Use
Frequently Asked Questions
What is OWASP API Security Top 10?
The OWASP API Security Top 10 covers the most critical API-specific vulnerabilities: broken object level authorization (API1), broken authentication (API2), broken object property level authorization (API3), unrestricted resource consumption (API4), broken function level authorization (API5), unrestricted access to sensitive business flows (API6), server-side request forgery (API7), security misconfiguration (API8), improper inventory management (API9), and unsafe consumption of APIs (API10).
Do you test GraphQL introspection?
Yes. GraphQL introspection is one of our first test cases — an enabled introspection endpoint exposes your entire schema to adversaries, including internal types, mutations, and queries that should not be publicly documented. We also test for GraphQL-specific attacks including injection, batching attacks, and field-level authorization bypasses.
How do you handle undocumented APIs?
We actively enumerate undocumented API endpoints using wordlists, JavaScript source analysis, mobile application decompilation (if in scope), and network traffic analysis. Undocumented endpoints are frequently the most vulnerable because they bypass the security review process that documented endpoints go through.
What about AI and LLM API endpoints?
LLM API endpoints that accept user-controlled prompts require additional testing beyond standard API security assessment — specifically prompt injection testing against the model layer. We include basic LLM endpoint testing in API Security Testing scope. For comprehensive OWASP LLM Top 10 coverage of LLM integrations, we recommend combining with the LLM Penetration Testing service.
Do I need written authorization?
Yes. Written authorization from a person with legal authority over all systems in scope is mandatory before testing begins. We provide a standard Authorization to Test (ATT) document. No testing begins without signed written authorization.
Ship Secure. Test Everything.
Book a free 30-minute security discovery call with our AI Security experts. We map your AI attack surface and identify your highest-risk vectors — actionable findings within days, CI/CD integration recommendations included.
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