APIs are the pipes that connect various applications and (micro)services. APIs have become an integral part of the web and mobile applications. These apps may exchange sensitive data like PII and financial or medical information. Thereby, it becomes an appealing target for hackers.

API testing is a type of software testing that analyzes an application program interface (API) to verify it fulfills its expected functionality, security, performance and reliability. The tests are performed either directly on the API or as part of integration testing.API testing focuses on analyzing the business logic as well as the security of the application and data responses. An API test is generally performed by making requests to one or more API endpoints and comparing the response with expected results. API security testing helps to discover potential security gaps. Thereby enabling the development team to fix them. It helps ensure that APIs are working as designed and intended to work. They provide visibility into gaps in integration that need to be rectified. Dynamic API Security Test and Static API Security Test are types of API Security assessment.

Benefits of API Testing:

API testing guarantees that connections among platforms are reliable, safe and scalable. Specific benefits include:

• API test automation requires less code than automated GUI tests, resulting in faster testing and a lower overall cost.
• API testing enables developers to access the app without a UI, helping the tester identify errors earlier in the development lifecycle -- rather than waiting for them to become bigger issues. This may save money as errors can be more efficiently resolved when caught early.
• API tests are technology and language independent. Data is exchanged using JSON or XML and it contains HTTP requests and responses.
• API tests use extreme conditions and inputs when analysing applications. This removes vulnerabilities and guards the app from malicious code and breakage.
• API tests can be integrated with GUI tests. For example, integration can enable new users to be created within the app before a GUI test is performed.

Our Approach to API Testing:

• Define Scope: Before an API Security assessment can take place, It needs to defines a clear scope of the assessment.
• Reconnaissance: Gathering as much information about the target API is essential when preparing for testing. This includes authentication credentials and other details such as IP addresses or URLs that may be used in test cases. The assembled information will assist us with understanding the working states of the association, which permits us to evaluate the risk precisely as the engagement progresses.
• Vulnerability analysis: Vulnerability analysis is the process of identifying vulnerabilities in an API, both application and network layers. To do this tester must log machine names along with sources on networks or applications services that are being used for accessing data from its target system(s).Using automated tools combined with manual techniques will help them identify risks most likely leading up to possible attack surfaces. Their focus can then be directed accordingly based on these findings once prioritization has occurred.
• Exploitation: Exploitation is where testers find vulnerabilities that may further discover genuine security gaps. This phase tests if these exploitable work as planned and documents findings for future reference so can avoid repeating any mistakes made during this stage.
• Reporting: After completing all of the aforementioned stages, we compile all of our findings into a report that is easy to read. The entire report will contain a high-level analysis of all the risks along with the remediation’s.