Researchers and attackers looking to exploit modern browsers are becoming more difficult. The introduction of exploit mitigations such as ASLR and DEP in Windows and sandboxes in Google Chrome and Internet Explorer a few years ago have made that process much more complicated, time-consuming and frustrating for researchers. With protected mode in IE and the sandbox in Chrome, that s a major obstacle, even for researchers at the top of their game, says Chaouki Bekrar, whose team won Pwn2Own this year after compromising Chrome and IE.
Source: https://threatpost.com/raising-bar-browser-attacks-031212/76315/