The GPL sources are insufficient. There is no description how to compile them, there is no script which does it, ...
I downloaded the firmware (128MB, which is HUGE) but that didn't bring anything either. The file starts with Salted__, which means that strong encryption is used.
So for the moment only the default attackpoints remain.
- Do a portscan, and try to find out which services are listening.
- Open the box and see if you can find a serial port.
- Format an USB stick ext2, create a symlink to / on it, and look if you can follow the link via samba, nfs, ftp, ... . - Have a critically look at the webinterface. Try to guess which user supplied data is passed to a linux shell. When not enough checking is done on the user input this could be a way to execute your own code.
- Create a page on the wiki
and share all collected information. Add photos of the PCB.
- Read the wiki pages of other iomega products. This product could have the same weaknesses.