There are bugs in Chrome but they’re very hard to exploit. I have a Chrome vulnerability right now but I don’t know how to exploit it. It’s really hard. The’ve got that sandbox model that’s hard to get out of. With Chrome, it’s a combination of things — you can’t execute on the heap, the OS protections in Windows and the Sandbox.
I might have this bug and I might be able to get code execution. But now you’r ein a sandbox and you have no permissions to do anything. You need another bug to get out of the sandbox. Now you need two bugs and two exploits. That raises the bar.