Final answer:
In a penetration test for web services with API endpoints, tools such as an intercepting proxy and activities like reconnaissance gathering and user acceptance testing are most likely to be used. These methods allow the tester to analyze traffic, gather information about the target system, and test authenticated APIs. so, option E is the correct answer
Step-by-step explanation:
During the scoping of a penetration test for web services with API endpoints, a penetration tester is likely to engage in several activities and utilize a variety of tools tailored to the specifics of the APIs being tested. These APIs are hosted on web application servers and vary in access requirements with some being available to unauthenticated users and others requiring authentication.
An intercepting proxy is often used in penetration testing to intercept and modify the requests and responses between the client and the web service, enabling the tester to analyze and manipulate the traffic for potential vulnerabilities. This is particularly useful for APIs because it allows detailed inspection and modification of API requests and responses.
Reconnaissance gathering is also essential, as it involves collecting information about the target system, which can reveal valuable insights about the system's design, implementation, and potential weaknesses. This could include details about the web services, API endpoints, and associated technologies.
Lastly, penetrating authenticated APIs will require methods to bypass or deal with authentication mechanisms, making user acceptance testing relevant. This is a process where the penetration tester mimics legitimate user behavior under controlled conditions to find vulnerabilities that might be exploited during normal use.