APIs Are the New Web App

95% of breached web applications in 2025 had an exploitable API flaw — and only 30% had ever had their APIs separately tested

Why APIs Need Their Own Test

APIs are different from the HTML web app sitting in front of them. They have no input-validation UI, expose every business operation directly, and live behind authentication models that are easy to misconfigure (JWT alg=none, OAuth scope confusion, signed-URL replay). The OWASP API Security Top 10 exists for a reason: BOLA, broken authentication, and excessive data exposure are exploited in the wild every week — Optus, T-Mobile, Twitter, and Peloton are all recent examples.

Aligned to OWASP API Security Top 10 (2023)
REST, GraphQL, gRPC, SOAP, and webhook protocols
Multi-role and multi-tenant authorization testing
JWT, OAuth 2.0, OIDC, API key, and mTLS authentication review
Rate limiting, quota, and resource-exhaustion testing
Specification-driven coverage from OpenAPI / Swagger / GraphQL schemas
API security testing

OWASP API Security Top 10 — Full Coverage

Every category, tested manually, with working proof-of-concept for every finding

API1Broken Object Level Authorization (BOLA)

The #1 API vulnerability industry-wide. We systematically test every object-reference parameter across every role and tenant — the bug class that hit Optus, T-Mobile, and Peloton.

API2Broken Authentication

JWT algorithm confusion (alg=none, RS→HS key confusion), token-replay, refresh-token theft, OAuth flow flaws, API-key entropy, and missing MFA on privileged endpoints.

API3Broken Object Property Authorization

Mass-assignment (writing fields you shouldn't), excessive data exposure (reading fields you shouldn't), and "ghost fields" inherited from internal models.

API4Unrestricted Resource Consumption

Rate-limit bypass, expensive-query abuse (especially GraphQL), batched-request amplification, and resource-quota flaws that drive cloud-cost denial-of-service.

API5Broken Function Level Authorization

Admin endpoints accessible to regular users, missing role checks on PATCH/DELETE, and HTTP-verb tampering against under-protected handlers.

API6Unrestricted Access to Sensitive Business Flows

Bulk-scrape protection, anti-fraud abuse, signup abuse, and replay of state-changing operations. The vulnerability class behind ticket-scalper bots and credential-stuffing campaigns.

API7Server Side Request Forgery

SSRF in webhook URLs, image-fetch endpoints, and integration callbacks — including blind SSRF that reaches cloud metadata services and internal admin panels.

API8Security Misconfiguration

Verbose error messages, missing security headers, default credentials, exposed admin interfaces, debug endpoints, and CORS misconfiguration.

API9Improper Inventory Management

Shadow APIs, deprecated endpoints still serving traffic, undocumented internal endpoints, and version-pivoting (v1 has the fix, v2 still vulnerable).

API10Unsafe Consumption of APIs

Trust assumptions in third-party API responses, SSRF through partner-API calls, and supply-chain trust-boundary failures.

Protocols We Cover

Deep expertise in every common API protocol

REST

Spec-driven coverage from your OpenAPI / Swagger document — or full reverse-engineered coverage if no spec exists.

GraphQL

Introspection abuse, query depth and complexity attacks, batched-query amplification, alias-based BOLA, and resolver-level injection.

gRPC

Reflection-based discovery, protobuf fuzzing, streaming-RPC abuse, and gRPC-Web bridging attacks. Specialist coverage few firms offer.

Webhooks & Events

HMAC-signature bypass, replay protection, SSRF via webhook URLs, and asynchronous-event trust-chain analysis.

API operators

Spec-Driven Coverage

Bring us an OpenAPI / Swagger / GraphQL schema and we'll test every endpoint, every method, every parameter — systematically and verifiably. No "we ran out of time" on production endpoints.

Multi-Role Authorization Matrix

We test every role against every endpoint — building a full authorization matrix that exposes the BOLA and function-level gaps automated tools cannot find.

Developer-Ready Findings

Every finding includes the exact request, the exact response, the exact fix — often with a sample patch for the framework you're using (Express, FastAPI, Spring, .NET, Rails).

Pairs Beautifully With Web App Testing

Test the web frontend and the API together: the most damaging vulnerabilities live in the trust boundary between them. We bundle both for ~30% less than separate engagements.

API Pentest FAQ

It's strongly preferred — a spec lets us guarantee coverage of every endpoint and method. If you don't have one, we can work from Postman collections, captured traffic, or perform discovery, but it adds time and reduces certainty of completeness.

GraphQL has a single endpoint but exposes far more authorization surface area through nested queries, aliases, and batched operations. Common GraphQL-specific issues include introspection enabled in production, query-depth/complexity DoS, and resolver-level authorization that doesn't check parent-object access. We have specialist coverage and tooling for it.

For most SaaS applications, yes. The most damaging vulnerabilities (mass-assignment, BOLA, privilege confusion) often live in the trust boundary between the UI and the API. Bundled engagements are ~30% cheaper than testing each in isolation. See our web app pentest page.

Most engagements run 1.5–3 weeks. Spec-driven tests of 50–100 endpoints fit cleanly in 2 weeks. Sprawling GraphQL schemas, undocumented APIs, or APIs with 200+ endpoints can run 3–5 weeks.

Yes. API pentest reports map to SOC 2 CC7.1 and PCI DSS 11.4 (penetration testing of public-facing applications). PCI DSS 4.0 added explicit requirements around API security — our reports cover that directly. We also align to ISO 27001 A.14 and HIPAA 164.308(a)(8).

Find the BOLA Before Anyone Else Does

OWASP API Top 10 coverage, REST + GraphQL + gRPC, spec-driven and developer-ready.

Scope an API Pentest