Penetration Testing
API Penetration Testing
APIs power the connections between your applications, and increasingly, between your organization and everyone it does business with. That connectivity is valuable, but every endpoint exposed is also a potential entry point, often with less scrutiny than the applications sitting in front of them.
The risk
Why it matters
APIs frequently handle sensitive data and business logic directly, sometimes with weaker authentication or validation than user-facing interfaces. A single broken access control or exposed endpoint can provide unauthorized access to sensitive data or critical business functions. As API adoption grows, so does the attack surface most teams aren't actively testing.
Our approach
Testing follows the OWASP API Security Top 10, combining automated scanning with manual, attacker-driven testing of business logic and access controls.
What's covered
Scope & deliverables
Assessment Scope
- REST, GraphQL & SOAP APIs
- Authentication & session handling
- Access control at object & function level
- Input validation & injection points
- Rate limiting & abuse prevention
Deliverables
- Executive summary
- Technical report with CVSS-rated findings
- Proof-of-concept evidence, where applicable
- Remediation guidance mapped to each finding
- Optional: One round of post-remediation retesting
Questions
Frequently asked questions
Which API types can be tested?
REST, GraphQL, and SOAP APIs, along with internal and third-party integrations where applicable.
Do you need API documentation to begin testing?
Documentation such as an OpenAPI/Swagger spec speeds up testing, but is not strictly required.
Will testing affect our live API or connected systems?
Testing is typically conducted in a staging environment. If production testing is necessary, safeguards are agreed upon in advance.
Do you provide a compliance-ready report?
Yes. Reports can be structured to support PCI-DSS, SOC 2, ISO 27001, and other frameworks based on your industry.
How is API Penetration Testing different from Web Application Penetration Testing?
Web Application Penetration Testing focuses on the browser-facing application, including user interfaces, authentication, and business logic. API Penetration Testing evaluates the backend interfaces that exchange data between systems, where issues such as broken object-level authorization, excessive data exposure, and insecure API logic may exist. Organizations using modern web or mobile applications often benefit from both assessments.
Go further
Related services
Organizations often pair this engagement with the assessments below for broader coverage.
Web Application Penetration Testing
Manual, attacker-simulated testing of browser-facing applications — authentication, access control, business logic and injection — aligned to the OWASP Top 10 and ASVS.
Learn MoreMobile Application Penetration Testing
Attacker-simulated testing of Android and iOS applications, covering local data storage, reverse engineering, authentication and the backend APIs behind them.
Learn MoreCloud Penetration Testing
Testing of AWS, Azure and GCP environments against CIS Benchmarks — IAM, storage permissions, network controls and cloud-native services.
Learn MoreVulnerability Assessment
Structured, repeatable identification of known weaknesses across your environment, with manual validation to cut false positives and prioritise real risk.
Learn More
Request a consultation
Tell us what you need assessed and we'll scope an engagement around it — timelines, safeguards, and deliverables agreed before any testing begins.