Server-Side Request Forgery (SSRF) in the Remote Browser Plugin in Sonatype Nexus Repository 2.x up to and including 2.15.2 allows unauthenticated remote attackers to exfiltrate proxy repository credentials via crafted HTTP requests.
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.