Set a password during a Ubuntu LiveCD session

https://help.ubuntu.com/community/LiveCD

Setting a Password

You can set a password during a LiveCD session by opening a terminal, and typing in:

$ sudo passwd ubuntu

http://nerdnotes.org/2006/05/can-i-ssh-into-ubuntu-live-cd/

Can I ’ssh into ubuntu live cd’ ?

Answer: Yes you can! But you first need to install the ssh daemon:
ubuntu@ubuntu:~$ sudo apt-get install openssh-server

The server is started automatically after installing. To login remotely, you’ll need to set the password for ubuntu:
ubuntu@ubuntu:~$ sudo passwd ubuntu
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
ubuntu@ubuntu:~$

…or create another user on the system:
ubuntu@ubuntu:~$ sudo adduser brammeleman
Adding user `brammeleman‘…
Adding new group `brammeleman’ (1000).
Adding new user `brammeleman‘ (1000) with group `brammeleman’.
Creating home directory `/home/brammeleman‘.
Copying files from `/etc/skel’
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
Changing the user information for brammeleman
Enter the new value, or press ENTER for the default
Full Name []: Brammeleman
Room Number []:
Work Phone []:
Home Phone []:
Other []:
Is the information correct? [y/N] y
ubuntu@ubuntu:~$

From another box, you can now login to the system running the live cd. Use the ubuntu username with the password you set or use the newly created account.