Not entirely bad.
It's just a bug in Safari (buffer overfl0w? Who knows? Comex does!).
This is a very OLD bug/problem.
This was how they jailbroke the older iOS's.
It was patched, then a new hole was found.

There was a patch for this problem the day it was released (available via Cydia).

Minkin is correct with the fact that it could happen with any device.
I'm going to guess that Android would be the easiest as it's open and everyone has access to it.