Server-Side Request Forgery (SSRF) is a web vulnerability where attackers trick a server into making unauthorized requests to internal or external systems.
An attacker sends a malicious URL in a request that the server processes as legitimate, making requests on the attacker's behalf.
The vulnerability can occur due to access control gaps, recovery features, or hidden interfaces.
Protecting against SSRF involves validating and sanitizing input URLs, using URL whitelists, and restricting internal service access.