To stop unwanted access to your DM500 change your password now

Open a Telnet session to your dreambox
from your PC in a terminal window type "telnet ipaddressofdreambox"

if you are running Gemini image you should see the following

* *
* The Gemini Project *
* *

welcome on your dreambox! - Kernel 2.6.9 (21:21:28).

dreambox login:

Enter user root
Enter password dreambox
You should now see

BusyBox v1.01 (2007.12.17-17:14+0000) Built-in shell (ash)
Enter 'help' for a list of built-in commands.

at this point type the command passwd
enter new password
re-enter new password
exit telnet

Happy sharing