This is huge:
Two security researchers have developed a new technique that essentially bypasses all of the memory protection safeguards in the Windows Vista operating system, an advance that many in the security community say will have far-reaching implications not only for Microsoft, but also on how the entire technology industry thinks about attacks.
In a presentation at the Black Hat briefings, Mark Dowd of IBM Internet Security Systems (ISS) and Alexander Sotirov, of VMware Inc. will discuss the new methods they've found to get around Vista protections such as Address Space Layout Randomization(ASLR), Data Execution Prevention (DEP) and others by using Java, ActiveX controls and .NET objects to load arbitrary content into Web browsers.
By taking advantage of the way that browsers, specifically Internet Explorer, handle active scripting and .NET objects, the pair have been able to load essentially whatever content they want into a location of their choice on a user's machine.
Paper here.
