This assumes that you can't break out of the VM, and that you can't gather information across the VM boundary. From http://news.ycombinator.com/item?id=2573618

This assumes that you can't break out of the VM, and that you can't gather information across the VM boundary. From http://news.ycombinator.com/item?id=2573618 http://news.ycombinator.com/item?id=2573618: > ... [C]onsider e.g. http://cseweb.ucsd.edu/~hovav/dist/cloudsec.pdf http://cseweb.ucsd.edu/~hovav/dist/cloudsec.pdf - cross-VM attacks are real, and extremely scary.