Preventing Server-Side Request Forgery

ASP.NET Core web applications are composed of different layers and components to make it a whole working system. Most of the time, it requires a backend service that will either process or provide data to the base web application. These disparate services interconnect to form a cohesive and functioning web application. This is either done in the form of a web service or a REST-based API hosted internally or externally from the system, and our code then calls the operations of these APIs and web services (or microservices).

However, without proper filtering or being able to validate the data that's been sent to these services, the host could start executing unexpected actions. This vulnerability is otherwise known as Server-Side Request Forgery (SSRF), with adversaries exploiting the lack of validation or sanitization available.

Getting ready

Run the sample app to verify that there are no build or compile errors. In your command...