Stop Data Leaks. Get API Pentesting.
APIs are the number one attack vector for modern web applications. We test REST, GraphQL, and SOAP endpoints.
Modern applications are built on APIs. While your frontend might be secure, your backend endpoints often expose sensitive data to anyone who knows how to ask. From Broken Object Level Authorization (BOLA) to Mass Assignment, API vulnerabilities can lead to massive data breaches without a single traditional “hack.” Our API Penetration Testing services peel back the UI layer to test the raw logic of your backend, ensuring your data is secure at the source.
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See What Our Clients Are Saying
Our clients consistently share that our collaborative partnership and transparent communication help them build stronger security programs.
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HAVEN6 has become our go-to partner for serious cloud security and penetration testing.
They’ve helped our clients harden AWS and Azure configurations, identify risky misconfigurations, and validate issues through focused penetration testing on networks, web apps, and APIs.
Ramin Lamei
TechCompass
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We have enjoyed working with HAVEN6. They were able to help us on some long-term agreements for pen testing.
Their personnel and management are easy to work with.
We look forward to our next project with them!
Joshua Weathers
Sugpiat Defense
The Drivers of API Pen Testing Requirements
APIs are the plumbing of the modern internet by connecting your mobile apps, web platforms, and third-party partners. You need to test them if:
You Have an Application
Web apps and Mobile apps are just pretty interfaces for APIs. The API is where the risk lives.
B2B Integrations
You expose APIs to partners or customers to allow them to fetch data programmatically.
Compliance (GDPR / PSD2)
Open Banking (PSD2) mandates testing of financial APIs. GDPR requires you cannot leak PII.
Rapid Development
Your devs use tools like Swagger or OpenAPI to auto-generate code, possibly introducing logic flaws.
Types of API Penetration Tests We Perform
We don’t just test standard websites; our expertise spans the entire spectrum of API architectures.
| Test Type | Description |
| REST API Penetration Testing | We test for CRUD (Create, Read, Update, Delete) logic flaws, JSON injection, and stateless authentication bypasses (JWT attacks). |
| GraphQL Penetration Testing | We look for specific GraphQL issues like Introspection abuse, deeply nested queries (DoS), and batching attacks that bypass rate limits. |
| SOAP API Penetration Testing | Legacy enterprise systems. We test for XML Injection (XXE), SAML manipulation, and WSDL exposure. |
| WebSocket Testing | Real-time communication channels. We look for Cross-Site WebSocket Hijacking (CSWSH) and unencrypted data streams. |
What Our API Pen Test Service Includes
We align our testing to strictly follow the OWASP API Security Top 10.
API Penetration Testing Deliverables
We provide the artifacts that executives need for clarity, auditors need for certification, and engineers need for bug fixes.
Executive Summary
A high-level risk profile of your entire API ecosystem, giving leadership a clear, non-technical overview.
Technical Findings Report
We provide the exact cURL commands used, Response Data proving a breach, and Remediation guidance.
Postman/Burp Collections
We provide the actual request files so that developers can replay the attack in their own environment.
Clean Retest Report
We conduct a comprehensive re-test to verify remediation. We issue a clean report for auditors.
API Penetration Testing Certifications
Our team holds industry-recognized certifications that reflect hands-on expertise across offensive security, cloud, applications, and compliance.
Offensive Security Certified Professional (OSCP)
Certified Information Systems Security Professional (CISSP)
GIAC Penetration Tester (GPEN)
GIAC Cloud Penetration Tester (GCPN)
GIAC Cloud Penetration Tester (GCPN)
CompTIA Security+, Network+, A+, Pentest+
GIAC Certified Incident Handler (GCIH)
AWS Certified Cloud Practitioner (CCP)
Microsoft AZ-900, SC-900
Certified Cloud Security Professional (CCSP)
Certified Ethical Hacker (CEH)
Burp Suite Certified Practitioner (Apprentice)
Web Application Penetration Tester (GWAPT)
Web App Penetration Tester (eWPT)
Systems Security Certified Practitioner (SSCP)
Palo Alto PSE Certifications
Why Clients Choose Us for API Pentesting
We specialize in complex languages (like GraphQL), manual business logic testing, finding critical flaws, and integrating into your CI/CD pipeline.
Business Logic Focus
Tools can find SQL injection. Tools cannot find that your API allows a user to buy a product for $0.00. We test the logic, so you save money.
GraphQL Expertise
Many testers treat GraphQL like REST. We don’t. We understand resolvers, schema definitions, and the specific complexity risks of graph databases.
Pipeline Integration
We can automate parts of this testing into your CI/CD pipeline using DAST tools, improving your development security posture.
Secure Your Connections.
Ensure your APIs are not the open door to your data.
API Penetration Testing: FAQs
Learn more information about the most frequently asked questions
What is API penetration testing?
An API pen test communicates directly with the API endpoints.
This allows our testers to manipulate requests, test business logic, and probe for weaknesses that are invisible from the client-side. Our methodology is built around the OWASP API Security Top 10, the industry-standard list of the most critical API risks, including:
- A01: Broken Object Level Authorization (BOLA): The #1 API vulnerability, where users can access data they shouldn’t be able to.
- A02: Broken Authentication: Flaws in how the API identifies a user.
- A05: Broken Function Level Authorization: Allowing users to access administrative functions.
- A03: Excessive Data Exposure: The API revealing more data than the client app needs.
- A04: Lack of Resources & Rate Limiting: Making the API vulnerable to denial-of-service attacks.
Who needs API penetration testing?
- SaaS Platforms: Your API is your product. Ensure it’s resilient and secure for your customers.
- Companies with Mobile Apps: The mobile app is often just a front-end for your APIs, making them the real target.
- FinTech and Banking: Secure financial transaction APIs and protect against fraud and data leakage to meet strict compliance.
- Healthcare (mHealth/EHR): Protect sensitive patient data (ePHI) transmitted via API to maintain HIPAA compliance.
- IoT Companies: Secure the device-to-cloud communication layer that underpins your entire product ecosystem.
- Organizations using a Microservices Architecture: Test the internal (East-West) APIs that connect your services.
API pen testing or web app pen testing?
While related, API pen testing focuses specifically on the ‘headless’ communication layer. It tests the API endpoints directly, without a user interface, to find flaws in authentication, authorization (like BOLA), data exposure, and rate limiting that might not be visible through a web front-end.
What do you need to start an API pen test?
To begin, we typically need a collection of the API endpoints (e.g., a Postman collection or Swagger/OpenAPI documentation), an explanation of the API’s functionality, and credentials for various user roles to test authentication and authorization controls thoroughly.
Do you test both REST and GraphQL APIs?
Yes. We have deep expertise in testing all major API architectures, including REST, GraphQL, SOAP, and gRPC. Our methodology is adapted to the unique attack surfaces of each technology.
Do you re-test after we fix the vulnerabilities?
Yes, re-testing is a critical part of our process. After you’ve remediated the identified vulnerabilities, we perform verification testing (usually included in our engagement) to ensure the fixes are effective and haven’t introduced new security flaws.
Is our application and data safe during the test?
Absolutely. All testing is performed by our trusted, in-house security professionals under a strict non-disclosure agreement (NDA). We use dedicated, secure testing environments and take extreme care to avoid disruption to your live services.
Do we need to provide API documentation?
Yes, highly recommended. While we can test without it (Black Box), providing a Swagger/OpenAPI definition or a Postman Collection allows us to test 100% of your endpoints, ensuring better coverage and ROI.
What is BOLA (Broken Object Level Authorization)?
BOLA is the #1 API vulnerability. It happens when an API endpoint (like /get_receipt?id=123) doesn’t check if the user requesting the receipt actually owns it. Attackers simply cycle through IDs (124, 125, 126) to steal everyone’s data.
How long does an API Pentest take?
It depends on the number of endpoints. A small API (10-20 endpoints) takes 3-5 days. A large enterprise API (100+ endpoints) can take 2-3 weeks.