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Adobe Warns of Critical Flash Bug, Already Being Exploited
Trailrunner7 writes "On the same day that it plans to release a patch for a critical flaw in Shockwave, Adobe confirmed on Thursday morning that there is a newly discovered bug in Flash that is being actively exploited already in attacks against Reader. The vulnerability affects Flash on all of the relevant platforms, including Android, as well as Reader on Windows and Mac, and won't be patched for nearly two weeks. The new Flash bug came to light early Thursday when a researcher posted information about the problem, as well as a Trojan that is exploiting it and dropping a pair of malicious files on vulnerable PCs. Researcher Mila Parkour tested the bug and posted a screenshot of the malicious files that a Trojan exploiting the vulnerability drops during its infection routine. Adobe has since confirmed the vulnerability and said that it is aware of the attacks against Reader."
I hope Apple and Adobe come to an agreement because I want to live on the edge too.
On Windows, you can force any program to run at Low IL (Integrity Level support requires Vista or above). Low IL processes, regardless of their nominal user permissions, can only write to Low IL folders. There are only a couple of these in the base install - %USERPROFILE%\AppData\Local\Low contains things like the Temporary Internet Files folder (IE runs at low IL by default).
Low IL processes also can't start other processes at higher integrity levels. If for some reason you need a higher level (the usual reason is saving files) you can have a "broker process" that runs at the standard level (Medium IL) and exposes some interprocedural communication to the Low IL process. Strictly speaking this opens a hole in your sandbox, but it's a lot easier to lock down that broker process since it's very special-purpose and has a very small attack surface. Also, the broker process can be used to present a warning to the user when it is invoked for anything potentially dangerous (IE's "Protected Mode" warning appears when the browser asks the broker process to start an external application).
It's not as customizable as AppArmor, but it's less complicated. Unfortunately, it also takes a little tweaking to find out how to set process or folder IL.
There's no place I could be, since I've found Serenity...
Here's an embarrassment for Adobe. An external researcher has created a tool called Blitzableiter, which is simply a Flash parser written in .Net. Its only job is to verify that any Flash you load is fully compliant with the Flash file format, and to hurl an exception if anything fails to parse correctly. I saw FX's presentation at DefCon and was suitably impressed.
The cool thing is that he claims it's caught every exploit, past and present, that he's been able to find to test it with.
Think about it. Someone external to Adobe is keeping Adobe's products safe simply by enforcing Adobe's own rules. Way to go, Adobe, you're completely awesome.
Configuring Blitzableiter to work in Firefox takes a little bit of work. He asked the NoScript guy to provide an external plugin mechanism, which launches Blitzableiter to check out the SWFs before they're permitted into the Shockwave player. So you have to load the NoScript extension, then configure it to run Blitzableiter. I look at it as a fairly small price to pay for safety.
I will say that it's pretty damn picky, and there's a lot of probably-safe-but-badly-written Flash out there that it won't let you load. Since there's actually very little Flash content I want to see anyway, it's not been a real problem for me. For expediency I put youtube.com in the exception list, just because I do trust the youtube player and don't feel I need to wait the extra two seconds to have it scanned every time I watch a video clip. Otherwise, it just rocks!
John