Authentication and session handling
Evaluating tokens, sessions, API keys, and client authentication mechanisms for weaknesses.
API Security & Penetration Testing
Secure the APIs that power your applications, integrations, and mobile clients with focused, methodical testing.
APIs are the backbone of modern systems – and a rich target for attackers
APIs expose core business functionality and data. They are often less visible than web front-ends, yet just as critical. Misconfigurations or logic flaws in APIs can lead directly to data leakage, account compromise, or service abuse.
Cyber Defence’s API tests focus specifically on how your APIs authenticate clients, control access, validate input, and handle edge cases.
Technologies we cover
We routinely test:
• RESTful APIs (JSON / XML)
• SOAP and legacy web services
• GraphQL APIs
• Mobile app and SPA backends
• Microservice and internal APIs exposed to partners or third parties
Testing can be performed against documentation, OpenAPI / Swagger definitions, or via traffic captured from clients.
Focus areas
Key API security areas we assess
Our approach aligns with OWASP API Security Top 10 and real-world attack patterns.
Authorisation and object-level access
Testing for IDOR, broken object-level authorisation, and context confusion between users and tenants.
Rate limiting and abuse protection
Assessing protections against brute force, enumeration, and resource exhaustion.
Input validation and data handling
Reviewing parameter handling, type enforcement, injection protection, and output encoding.
Error handling and information disclosure
Identifying verbose errors, stack traces, and metadata leaks that aid attacker reconnaissance.
Business logic and workflow abuse
Exploring flows and multi-step operations for logic flaws and misuse scenarios specific to your API.
API testing process
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1. Discovery and documentation review
Understanding API endpoints, parameters, roles, and expected behaviour from documentation, schemas, and traffic.
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2. Mapping and test case design
Planning test cases for authentication, authorisation, input handling, and workflow edge cases.
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3. Manual and automated testing
Combining specialist tooling with targeted manual testing to uncover weaknesses.
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4. Impact analysis and exploitation chains
Identifying how discovered issues could be chained into data exfiltration or account compromise.
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5. Reporting and developer guidance
Delivering clear, reproducible findings with code-level and design-level remediation advice.
Secure the APIs your applications rely on
Provide your API definitions, example requests, and use cases, and we will design a focused test that reflects how your APIs are actually used.