Manual, methodical testing of REST, GraphQL, and gRPC APIs. We cover the full OWASP API Security Top 10 plus the API-specific attack patterns that automated scanners are blind to.
Modern applications expose more API surface than UI surface. Most security tooling was built for web apps and does poorly at APIs. Testing your APIs the way real threat actors test them requires a different skill set and a different approach.
API security is its own discipline. The OWASP API Security Top 10 exists because the attack patterns against APIs are different from the patterns against rendered web applications. Broken object-level authorization, broken object property-level authorization, mass assignment, and resource consumption abuse all happen at the API layer, not the UI layer, and a UI-focused web pentest will miss most of them.
Our API engagements work directly against the API surface. We use the API the way a determined integrator or threat actor would: discovering endpoints, enumerating object identifiers, attempting authorization bypass at every endpoint and parameter, and chaining findings into demonstrated impact.
The most common and damaging class of API vulnerability. Every endpoint that accepts an object identifier (user ID, order ID, document ID) is a potential authorization boundary. We enumerate them all and test whether each enforces the authorization it should.
JWT handling errors, weak token signing, OAuth flow weaknesses, broken multi-factor authentication, and session management mistakes specific to APIs.
Mass assignment vulnerabilities and excessive data exposure. The cases where the API accepts more fields than it should from the client, or returns more fields than the client should see. Both are common and both can lead to privilege escalation or sensitive data leakage.
Rate limiting and quota enforcement. APIs without effective rate limiting are easy targets for credential stuffing, scraping, and denial-of-service. We test what your API allows under hostile load.
Vertical privilege escalation: regular users accessing administrative endpoints, anonymous users accessing authenticated endpoints, lower-privilege roles invoking higher-privilege functions.
APIs that fetch URLs on behalf of clients are common SSRF vectors. Webhook configuration, image fetching, document import, and integration endpoints all need careful testing.
Introspection abuse, query depth attacks, batching attacks, alias abuse, field-level authorization gaps, and the unique challenges of authorization in a GraphQL schema.
When your API trusts data from a third-party API and feeds it back to clients, that trust boundary needs validation. We test how your API handles unexpected or hostile responses from its upstream dependencies.
Active testing typically runs one to two weeks. Engagements are most effective when you provide an API specification (OpenAPI, Swagger, GraphQL schema, or Postman collection) plus credentials at each privilege level. Without a spec we will discover endpoints, but coverage is more thorough and time-efficient when we start with the documented surface.
The engagement follows our standard five-phase methodology.
Yes. Internal APIs are often less hardened than public-facing ones because the assumption is "nobody can reach them". When an attacker is already inside (which is the assumption for most modern threat modeling), internal APIs become a critical attack surface.
Yes, but the engagement is more efficient when you do. Without a spec we discover endpoints by intercepting client traffic and analyzing client code, which works but takes longer.
Manually at every endpoint, programmatically for high-volume parameters. We script the enumeration and use multiple test accounts to compare authorization decisions across roles. We focus the manual work on the highest-impact endpoints.
No. We respect rate limits, avoid destructive operations, and coordinate any load-relevant tests with your team. Rate limiting itself is something we test, but in a controlled way that does not affect legitimate users.
Yes. The API behind a mobile app is exactly what an attacker would target, since the mobile app is just a thin client. We intercept the API traffic from the mobile app and test the API directly, which is more efficient than testing through the app UI.
Tell us about the API, the spec if you have one, and your timeline. We will respond within one business day.