At the most basic level, API security testing helps identify and prevent vulnerabilities and their associated potential organizational risk.
Specifically, API security testing is fine-tuned to both the API being tested and an organization’s overall strategy and best practices. API scanners work at a deeper level, examining the APIs that power single-page web apps, IoT devices, or mobile apps. By understanding what an API expects as input, API scanners can intelligently fuzz data to uncover hidden bugs.
API security testing tools also help enforce the correctness of an API, scanning the business logic of an API rather than just the input validation provided by the front end.
API security testing can also help identify where an API diverges from published API specifications. For example, if a specific endpoint should respond with a particular HTTP status but another is detected during a scan, the testers will alert the appropriate stakeholder. This helps ensure that the developers who leverage the APIs have an experience consistent with published specifications.