Web Shell

Netcat, is the Swiss army knife of connections between servers.
It can listen, connect and launch shells.

Older versions had the -e or -c option to launch a shell. Recent versions do not have this option anymore for security reasons.
On Kali there is a version 1.10 in :

/usr/bin/nc -h
    -e shell commands : program to execute
    -c shell commands : program to execute
    -l                : listen mode
    -v                : verbose
    -p port           : local port number

Connect to port 3000 on 10.0.0.11 server:

/usr/bin/nc 10.0.0.11 3000