Sometime ago, I’ve received SSH access to a host which was quite restricted. Lots of executables are denied execution, as it was supposed to be only for learning, so no network access curl/wget/nc/socat/ssh -(L|D|R)
, or compilers, but then it’s got bash. Here is a tiny hack to connect to IRC from that host:
1. Create a file irc.sh
on $host:
#!bash exec 3<>/dev/tcp/irc.freenode.net/7070 cat <&3 & cat >&3
2. Add following line to inetd
/xinetd
(or netcat):
sua stream tcp nowait $localuser /usr/bin/ssh ssh -i $privatekey -l $user $host bash irc.sh
3. Now connect your IRC client to localhost:sua
(localhost:14001
).
This is only a fun hack, and not something used to regularly circumvent access. 😛