Arduino Yún shield password reset
Try connecting via ethernet to 192.168.255.1 with root/root

The SSH access for Dragrove is:
IP: 192.168.255.1 on LAN port. If you want to connect to the Dragrove via WiFi, the IP should be 192.168.1.108.
Username: root
Password: root

http://www.seeedstudio.com/wiki/Dragrove_-_Generic_gateway_for_internet_of_things