Lately there's been a big focus on kernel vulnerabilities. They're nasty (even when strictly local) because they bypass everything, and there seem to be a lot of them lurking around. But how much malware in the wild actually uses these vulnerabilites? e.g. I know Stuxnet and Duqu use kernel vulnerabilities, and both have IIRC made it into the wild. Are there any others? More importantly, how many cases have there been of malware exploiting a kernel hole before it was patched? We know these vulnerabilies exist, and are nasty; but how relevant are they to end users in most cases? Who's using them, aside from governments?