Your APIs Talk to Everything, so They Get Attacked First
API Security Testing Services
APIs now carry more sensitive data than the applications sitting in front of them, yet they are often the least tested part of the stack. We manually assess your REST, GraphQL and SOAP APIs for the authorisation and data exposure flaws that automated tools consistently miss.
- Certified Experts
- OSCP, CEH, CRTP & industry-certified testers.
- Real-World Approach
- Manual testing with real-world attack techniques.
- Actionable Reporting
- Detailed findings with clear risk ratings and remediation.
- Confidential & Secure
- Strict NDA, data protection & privacy practices.
// About API Security Testing
Securing the Layer Your Application Depends On
Modern products are built on APIs, from mobile back ends to partner integrations and internal microservices. Each endpoint is a potential door into your data. The most damaging API flaws, one user pulling another user's records or an endpoint that accepts requests it should reject, rarely show up in a standard scan.
Our testers work through your API documentation, authentication flows and object level permissions by hand. We map exactly what an authenticated attacker could reach that they should not be able to. We test APIs for UK organisations, whether they sit behind a mobile app, a partner integration or a public developer platform.
- Full OWASP API Top 10 Coverage
- Authorisation Flaws Found by Hand
- Clear, Evidence-Backed Reporting
- Support for REST, GraphQL and SOAP
// Coverage
What We Cover
REST API Testing
Full assessment of authentication, authorisation and input handling across REST endpoints.
GraphQL Testing
Review of query depth abuse, introspection exposure and field level permissions.
SOAP and Legacy API Testing
Assessment of older XML based API implementations still in production use.
Third Party and Partner APIs
Testing of the integrations your business exposes to external partners.
Internal Microservice APIs
Assessment of service to service communication and internal trust boundaries.
Authentication Mechanisms
Testing of OAuth 2.0, JWT and API key implementations for weaknesses.
// Methodology
Our API Testing Process
- 01
Scoping and Documentation Review
We agree scope and review your API specification, whether OpenAPI, Postman collection or raw documentation.
- 02
Endpoint Mapping
We map every accessible endpoint, method and parameter, including ones missing from the documentation.
- 03
Manual Security Testing
We test authentication, authorisation and business logic by hand across every role your API supports.
- 04
Exploitation and Validation
We confirm real world impact for every finding, without disrupting live data.
- 05
Reporting and Retest
You receive a prioritised report and a free retest once fixes are deployed.
// Ready when you are
Put your api security testing services to the test.
// Impact
Why API Security Testing Matters
APIs Are Rarely Rate Limited by Default
A single misconfigured endpoint can allow automated scraping of your entire user base.
// How We Test Your APIs
- Endpoint discovery and API documentation review
- Authentication and token handling testing
- Broken object level authorisation testing
- Broken function level authorisation testing
- Mass assignment and excessive data exposure checks
- Rate limiting and resource consumption testing
- Injection and input validation testing
What you get
// Tools We Use
// Why Choose Pluto Cyber Security
Testers Who Understand Modern API Architecture
API testing is not a checklist exercise for us. Our consultants work with REST, GraphQL and microservice architectures every week, which means we know where authorisation logic tends to break long before we open Burp Suite.
API-Specific Expertise
Our testers specialise in the authorisation and logic flaws unique to API architectures.
Framework Aligned
Every test is structured around the OWASP API Security Top 10 and a CREST-aligned methodology.
Developer-Friendly Reports
Findings are written for engineers to fix quickly, not just for auditors to file away.
Confidential Engagement
All access, tokens and data remain protected under strict NDA throughout.
Web application testing covers the full user-facing application. API testing focuses specifically on the endpoints, authorisation logic and data exposure behind that application, including ones the browser never directly reveals.
// Related services
Explore Related Services.
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Ready to Scope Your API Security Testing Services?
Tell us what you need tested. We reply with honest guidance and a fixed-scope quote, usually within one business day.