Almost every HTTP server, language, and web framework has at one point had a vulnerability that exposes configuration or environment variables. The fundamental

Almost every HTTP server, language, and web framework has at one point had a vulnerability that exposes configuration or environment variables. The fundamental problem is that no matter what language and server combination you choose, it was never written for hostile environments. Exposing an IP address of an internal server is considered a very low risk vulnerability (as compared to say RCE), so very little work is put into auditing for such risks.