CrushFTP 9.x and 10.x through 10.8.4 and 11.x through 11.3.1 allows SSRF via the host and port parameters in a command=telnetSocket request to the /WebInterface/function/ URI.
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.