Cyber Security Testing
API Penetration Testing
Identify vulnerabilities in your APIs before they can be exploited by hackers. Penetration testing strengthens your digital assets and protects your business.
What Is API Penetration Testing?
API Penetration Testing is a targeted security assessment focusing on your application’s Application Programming Interface (API). While it may not be as comprehensive as a full web application penetration test, it is a crucial step in securing the data exchange layer of your application.
This type of testing simulates real-world attacks on API endpoints to uncover common vulnerabilities such as broken authentication, inadequate access controls, insecure data exposure, and injection flaws. The goal is to ensure that your API can withstand malicious input and unauthorised access attempts without compromising data integrity or functionality.
Common Security Risks in APIs
Unauthorised Access to Resources or Data (e.g., users, orders, resources)
APIs frequently expose endpoints that accept object IDs. Without strict authorisation checks, attackers can manipulate these IDs to access data they should not be able to see. This represents one of the most prevalent and serious API vulnerabilities.
What We Test For:
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ID tampering to access unauthorised resources
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Missing object-level access controls
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Insecure direct object references (IDOR)
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Multi-tenant access bypass
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Role-based access enforcement
Flaws in login, token handling, and session management
Authentication weaknesses can allow attackers to impersonate users or gain unauthorised access. These flaws often stem from poor token handling, weak password policies, or improper session management.
What We Test For:
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Weak or missing token validation
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JWT and OAuth implementation issues
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Token reuse and session hijacking
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Brute force login vulnerabilities
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Insecure password reset flows
API responses could be leaking more information than necessary
APIs should only return data that the client needs. However, many expose internal objects or sensitive information unintentionally, making it easier for attackers to gather intelligence or exploit other issues.
What We Test For:
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Overexposed fields in JSON/XML responses
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Leaked internal IDs, emails, or tokens
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Lack of output filtering or field whitelisting
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Sensitive data in verbose error messages
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Debug or dev endpoints returning full objects
APIs with no protection against brute force or abuse
Without proper rate limiting, APIs are vulnerable to brute-force attacks, credential stuffing, and data scraping. Attackers can automate the abuse of endpoints that were meant for controlled or limited access.
What We Test For:
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Missing or weak rate-limiting controls
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No lockout after repeated failed logins
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Abuse of password reset or auth endpoints
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Unrestricted enumeration of users or data
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Mass data scraping from public endpoints
SQL Injection, Command Injection, etc.
Injection issues occur when untrusted data is sent to an interpreter as part of a command or API query. These vulnerabilities can allow attackers to access, modify, or destroy backend data. They are often the result of insufficient input validation or insecure coding practices.
What We Test For:
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SQL Injection
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OS Command Injection
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LDAP Injection
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XML Injection
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Input validation flaws