Performing server-side request forgery

Server-side request forgery (SSRF) is a security vulnerability that's found within web applications that allows a threat actor to retrieve resources from other systems on the network via the vulnerable web application. Imagine you're a threat actor and have discovered a vulnerable web application that allows you to proxy your attacks to other systems on the same network connection, allowing you to perform port scanning and file retrieval.

SSRF is possible when a web application does not validate and sanitize the user-supplied URL during the HTTP request messages. If a threat actor can perform SSRF on a web application that is accessible over the internet, the threat actor can leverage the security flaw and bypass the firewall, access control lists (ACLs), and other security controls implemented by the organization.

In the following lab exercise, you will discover the security risks involved when using a web application that allows...