Setting up incredibly insecure SSH on Debian

Sometimes it’s useful to have incredibly insecure SSH on a machine, such that it allows logging in as root without a password. It’s pretty self explanatory that you shouldn’t enable this on a box connected to an unsecured network, but just to be clear;

Now that we’ve got that out of the way, let’s get onto configuring this thing!

It’s pretty straightforward to get this set up;

1. Remove root’s password.

   passwd -d root

2. Enable both root login and logging in without a password.

   Edit /etc/ssh/sshd_config and change these options;

   PermitRootLogin yes
   PermitEmptyPasswords yes

3. The special sauce: Mark ssh as a “secure TTY”.

   Edit /etc/securetty and add ssh to the end;

   ssh

   This step is the not-so-obvious one, and the reason I wrote this post in the first place!

4. You’re done! You can now SSH into your box as root without a password;

   $ ssh root@example.com
   $ id
   uid=0(root) gid=0(root) groups=0(root)

Source: Super User