During a security assessment of a web application, a penetration tester discovers a vulnerability that allows users to pass a URL to the web application and retrieve information from an internal web…

Input validation is crucial to prevent SSRF by ensuring that URLs or parameters passed to the web application are restricted to legitimate, expected values and do not allow arbitrary internal or external requests. This sanitizes and validates all user-supplied input before it is used to make server-side requests.

Secrets management is about securely storing and managing credentials, which is not the primary fix for an SSRF vulnerability.

Network segmentation limits the impact of an SSRF attack by isolating the web application from internal networks and systems that it should not access. By placing the vulnerable application in a segmented network, even if an attacker successfully exploits SSRF, they would be unable to reach other sensitive internal resources.

Certificate management deals with SSL/TLS certificates and their lifecycle, unrelated to preventing a web application from making unauthorized requests.

Patch management addresses software bugs and vulnerabilities, but doesn't specifically prevent the logic flaw of allowing arbitrary URL requests without validation.

Multifactor authentication secures user logins but does not prevent a server-side vulnerability exploited by an already authenticated or unauthenticated attacker.