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Google Exposes How Malicious Sites Can Exploit Microsoft Edge (zdnet.com)

Google's Project Zero team has published details of an unfixed bypass for an important exploit-mitigation technique in Edge. From a report: The mitigation, Arbitrary Code Guard (ACG), arrived in the Windows 10 Creators Update to help thwart web attacks that attempt to load malicious code into memory. The defense ensures that only properly signed code can be mapped into memory. However, as Microsoft explains, Just-in-Time (JIT) compilers used in modern web browsers create a problem for ACG. JIT compilers transform JavaScript into native code, some of which is unsigned and runs in a content process.

To ensure JIT compilers work with ACG enabled, Microsoft put Edge's JIT compiling in a separate process that runs in its own isolated sandbox. Microsoft said this move was "a non-trivial engineering task." "The JIT process is responsible for compiling JavaScript to native code and mapping it into the requesting content process. In this way, the content process itself is never allowed to directly map or modify its own JIT code pages," Microsoft says. Google's Project Zero found an issue is created by the way the JIT process writes executable data into the content process.

4 of 51 comments (clear)

  1. Here's an idea. by Anonymous Coward · · Score: 5, Insightful

    Let's ditch Javascript and go back to usable websites that don't require a fucking quad core CPU and 8GB of RAM just to view.

    It's hard to exploit something when you can't run arbitrary code on it at all. "But muh infinite scrolling-" fuck your infinite scrolling. I've yet to see a website implement that properly where my browser tab didn't land up consuming 4 fucking gigabytes of RAM after 20 or so pages of stuff. God forbid I should refresh the page, lest I lose my position within your endless stream of crap content and advertisements.

    The most usable websites I've seen these days are the ones that actually have pages I can click through, layout things in a clean and logical manner, and don't feel the need to animate every fucking widget that appears on the screen. Case in point:

    http://www.motherfuckingwebsite.com

    1. Re:Here's an idea. by gnick · · Score: 3

      I tried promoting Opera here on /. for many years and as usual, nobody listens.

      I like Opera, but you're not going to find many users here. The few there were abandoned it when it was sold to the Chinese in 2016. For some reason, people don't trust the Chinese. People have looked pretty hard at it and the code was even leaked last year, but for some reason people trust MS & Google more than "Golden Brick Capital Private Equity Fund I Limited Partnership".

      --
      He's getting rather old, but he's a good mouse.
    2. Re:Here's an idea. by gnick · · Score: 2

      You're suggesting that "Golden Brick Capital Private Equity Fund I Limited Partnership" could be a shell? Surely you jest!

      It's like they didn't even try.

      --
      He's getting rather old, but he's a good mouse.
    3. Re:Here's an idea. by DarkOx · · Score: 2

      You realize Opera is just webkit now. So there is no point really. You might as well just use chromium

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      Repeal the 17th Amendment TODAY! Also Please Read http://www.gnu.org/philosophy/right-to-read.html