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API / Security

API Security
Testing

Penetration testing for REST, GraphQL and service APIs — focused on the authentication, authorization, logic and abuse cases that expose data and functionality far beyond what a scanner can find.

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Service Overview

APIs are where most modern applications keep their logic and data — and where most modern breaches happen. API Security Testing focuses on how endpoints authenticate callers, enforce authorization, validate input and handle the workflows your business depends on.

We map every endpoint, parameter and object the API exposes, then test how it behaves when called in ways it was never meant to be — across roles, objects, sequences and rate limits. The most damaging API issues are rarely injection; they are broken object-level and function-level authorization.

Each finding is validated with a concrete request-and-response proof-of-concept so you can see exactly what an attacker could read, change or trigger — and exactly which control failed to stop them.

// Authorization Is The Attack Surface

When valid requests reach data they shouldn’t

The most serious API flaws use perfectly valid requests to reach other users’ data or privileged functions. We test every endpoint across roles and objects to prove where authorization breaks down — the OWASP API Top 10 in practice.

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Benefits

[01]

REST and GraphQL expertise

We test both, including GraphQL-specific risks like introspection, nested queries, batching abuse and resolver-level authorization.

[02]

Authorization-first testing

We probe object-level and function-level access control across every role, the flaws that cause the majority of real API breaches.

[03]

Logic and abuse coverage

Beyond CRUD, we test sequences, race conditions, rate-limit bypass and workflow abuse that automated tools cannot reason about.

[04]

Developer-ready findings

Each issue comes with the exact request, response and fix guidance, so your engineers can reproduce and remediate immediately.

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Why Choose HackersForce

A structured assessment of every endpoint the API exposes — testing how it authenticates, authorizes, validates and rate-limits requests across roles, objects and workflows.

▸ How we approach testing

We build a complete map of the API’s endpoints, objects and roles, then systematically call them in ways they were never intended to be used to find where access control and logic break.

✓ Authentication mechanisms and token handling (JWT, OAuth, API keys)
✓ Object-level authorization across users and roles (BOLA / IDOR)
✓ Function-level authorization on privileged endpoints (BFLA)
✓ Excessive data exposure in responses and verbose objects
✓ Input validation and injection across parameters and headers
✓ Mass assignment and unexpected property binding
✓ Rate-limiting, throttling and resource-consumption controls
✓ Business-logic and multi-step workflow abuse
✓ GraphQL introspection, nested queries and batching abuse
✓ Improper handling of HTTP methods and content types
✓ Error handling and information disclosure
✓ Security misconfiguration across the API gateway and services

Engagements follow a repeatable, standards-aligned process so coverage is consistent and every finding is traceable from discovery to remediation.

01

Scoping & Rules of Engagement

We agree endpoints, documentation, roles and constraints in writing before testing begins.

02

Schema & Endpoint Mapping

We enumerate every endpoint, parameter and object using docs, specs and traffic to build a complete attack surface.

03

Authentication & Authorization Testing

We test how callers are identified and what each role can reach, focusing on object- and function-level access control.

04

Abuse & Logic Testing

We test input handling, mass assignment, rate limits, sequences and workflow abuse against real impact.

05

Reporting & Free Retest

You get an executive summary and technical report, then we retest your fixes at no extra cost.

A sample of the issue classes we routinely uncover in APIs — aligned to the OWASP API Security Top 10, with each tied to a concrete proof-of-concept.

⚠ Broken object-level authorization (BOLA / IDOR)
⚠ Broken function-level authorization (BFLA)
⚠ Broken authentication & weak tokens
⚠ Excessive data exposure
⚠ Mass assignment
⚠ Unrestricted resource consumption
⚠ Injection (SQL, NoSQL, command)
⚠ Business-logic & workflow abuse
⚠ GraphQL introspection & query abuse
⚠ Security misconfiguration
⚠ Improper inventory & shadow endpoints
⚠ Unsafe consumption of third-party APIs
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FAQs

Yes. We test REST, GraphQL and other service APIs, including GraphQL-specific risks like introspection, deeply nested queries, batching and resolver-level authorization.
Documentation, an OpenAPI/Swagger spec or a Postman collection helps us achieve complete coverage quickly. Where none exists, we map the API from observed traffic and the application itself.
Yes — and we strongly recommend it. Many of the most serious API flaws only appear when comparing what different roles can reach, so we ask for accounts across each privilege level.
There is overlap, but API testing is endpoint- and authorization-centric rather than UI-driven. We focus on the request layer directly, which exposes object- and function-level access issues a UI-driven test can miss.
Yes, where they are in scope and you have authority to test them. Internal and partner APIs often assume trust that does not hold up, so they are valuable to assess.
An executive summary and a detailed technical report with validated findings, exact request/response evidence, CVSS scoring and prioritised remediation — plus a free retest after fixes.

Ready to test your API?

Share your endpoints or spec. We’ll define scope across roles and services and give you a fixed quote with no surprises.

Schedule a Call → Request Sample Report