Create user with a blank password

Solution 1:

Why would you want a user without a password? That's just asking for trouble specially if this machine is on the Internet or a network. Why not setup a password for the user but have them auto-login. If you still want to have that done, then just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo useradd <user_name>
sudo passwd -d <user_name>

To enable auto-login, create the user, type in a password, and check Don't ask for password on login.

Solution 2:

It is possible, but not as easy as you may think. Normally, a user without password can not login on a Linux system. So you have to set a password hash which maches an empty string.

Have a look at this discussion to learn how to do it. Short answer is to put U6aMy0wojraho for the hash of the blank password in /etc/passwd, like TheUsersName:U6aMy0wojraho:...

Solution 3:

Create an user with empty password

sudo useradd test-user-0
echo test-user-0:U6aMy0wojraho | sudo chpasswd -e
su test-user-0

The password prompt still shows unfortunately.

But if you just hit enter without typing anything, and it logins as the user test-user-0.

The -e flags tells chpasswd that the password is already encrypted, and U6aMy0wojraho is the hash of the empty string.

Tested on Ubuntu 18.04.

BusyBox autologin

On the terminal at least, you don't need to create an user without a password to allow someone to not type their passwords everytime, hacking inittab a bit is enough: https://unix.stackexchange.com/questions/299408/how-to-login-automatically-without-typing-the-root-username-or-password-in-build