[shubb]

That would look to be correct, see here for example: http://hackers2devnull.blogspot.co.uk/2013/07/exploiting-pos...

In which case, I woner why more sites (or evil ads via an ad network) don't attack our home routers?

[chc]

Probably because it isn't really necessary — it's easier just to own the user's PC the old-fashioned way.