What is API Penetration Testing?

API penetration testing checks whether attackers can use your APIs to reach data or functions that are not meant for them.

We test REST, GraphQL and older APIs for flaws in login, permissions and business logic. An ethical hacker validates every finding.

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Example finding from a pentest reportSEC-012

High risk

One extra field in an API request lets a normal user make themselves an administrator

Impact: That user can then manage every account and all data in the application.
Fix first: Let the API change only the fields a user is allowed to edit.

Validated by an ethical hackerRetest included

What does the API pentest scope cover?

Authentication and session management

Broken Object Level Authorization (BOLA/IDOR)

Broken Function Level Authorization

Mass assignment and parameter tampering

Injection flaws (SQL, NoSQL, command injection)

GraphQL introspection and batching abuse

Rate limiting and resource exhaustion

Sensitive data exposure and error handling

CRA for software and digital products: what should you have tested?

The Cyber Resilience Act (CRA) is European regulation for products with digital elements, such as software, apps and smart devices. Since 11 September 2026, manufacturers must report actively exploited vulnerabilities and severe incidents through the ENISA platform. The remaining obligations apply from 11 December 2027.

A pentest shows whether a vulnerability can really be exploited and what the impact is. That helps you judge faster what to report and fix.

How do we test your APIs?

Authentication Testing

We test login flows, token handling, session management, and OAuth implementation for flaws that allow account takeover, token forgery, or unauthorized access.

Authorization and Access Control

We systematically test whether users can access resources, functions, or data they should not. BOLA, BFLA, and privilege escalation via parameter manipulation are validated across all identified endpoints.

Business Logic and Injection

We go beyond the OWASP list and test for business logic flaws specific to your API. This includes injection in all input fields, GraphQL-specific attack vectors, and chained vulnerabilities that automated scanners miss.

Frequently asked questions

We test REST APIs, GraphQL APIs, and legacy SOAP or XML-based interfaces. We also cover mobile app backends, internal microservice APIs, and third-party integrations where scope allows.

Yes, we use the OWASP API Security Top 10 as a baseline but go beyond it. Real attackers do not stop at a checklist. We test business logic, chained vulnerabilities, and environment-specific weaknesses that automated tools and checklist approaches miss.

Typically two to five days, depending on the number of endpoints, authentication complexity, and scope. We provide a timeline estimate after reviewing your API documentation or a sample collection.

An executive summary, a technical report with evidence per finding, severity ratings aligned to CVSS, and prioritized remediation steps. After your fixes, we retest them. The retest is included.

How does an API pentest work?

Scope and endpoint mapping

We review your API documentation or OpenAPI spec and map all accessible endpoints, including undocumented or legacy routes.

Authentication and authorization testing

We test all auth flows and systematically verify access control across roles, users, and data objects.

Active exploitation and chaining

We attempt to chain findings and validate exploitability under realistic attack conditions.

Report and remediate

Technical report with evidence, severity ratings, and clear fixes. The retest after remediation is included.

Test Your APIs Before an Attacker Does

Identify authentication flaws, authorization bypasses, and injection vulnerabilities across your REST or GraphQL API surface.