Are there security risks for an iOS device?
Currently there aren't any vulnerabilities that can be used remotely to access data like this that I know of.

If someone had physical access to the device, then they could access any data on it, as the disk isn't encrypted. Of course, the high retail value etc would mean most thieves would likely just wipe and sell it, rather than try to extract data.

In short, right now there aren't any active exploits that allow remote data access (though there have been ones in the past involving tiffs and pdfs that may have allowed this).

If the device was stolen, you are out of luck though, even with a passcode lock.

It's possible to set up two things to mitigate this:


Get the passcode wrong 10 times, and device is wiped
Find my iPhone app from iCloud allows you to remotely wipe the device