Sourcegraph vulnerable to Comand Injection via gitserver

Sourcegraph is a code intelligence platform. In versions prior to 4.1.0 a command Injection vulnerability existed in the gitserver service, present in all Sourcegraph deployments. This vulnerability was caused by a lack of input validation on the host parameter of the `/list-gitolite` endpoint. It was possible to send a crafted request to gitserver that would execute commands inside the container. Successful exploitation requires the ability to send local requests to gitserver. The issue is patched in version 4.1.0.