Typo

Challenge Statement

Author: @JohnHammond

Gosh darnit, I keep entering a typo in my Linux command prompt!

Note: This challenge was accompanied with a per-user instance

Solution

This challenge requires us to SSH into a provisioned per-user instance with the given password. While doing so, I was met with a train.

If you have been around the linux community for sometime, you should have been familiar with the sl command. This command was intended to show the user that they mistyped ls in a fun way.

But our problem is the connection shows us the train and exits without providing us a chance to interact with the instance. I thought it was because of hard-coded .bashrc file that contained sl command and made the shell exit.

So I worked around it with by specifying the shell to use when connecting to the instance. Since my theory was that it was because of .bashrc file, I intended to use another shell other than bash. Since almost all system contains the sh shell, I thought of using it.

With the following command, I SSHed into the instance and this time I got an interactive shell.

ssh -p <port> user@challenge.ctf.games -t /bin/sh

The flag was in a flag.txt in the directory right there.