Sunncomm/Mediamax software fix FLAWED



Once more in the continuing story…. According to freedom-to-tinker, the “fix” released today for the SunnComm/Mediamax DRM software (the “other” DRM software on sony/bmg discs). Is fatally flawed. The problem the software initially poses is much worse than the company lets on in their release and their advise is…. 1) don’t play a mediamax protected disc in your pc. 2)don’t use the fix, 3) don’t use the old uninstaller.


So, this was out, what…. 3, 4 hours before it was announced there were serious flaws with it? Ouch.

Here’s some of their analysis of the press release…

Alex Halderman has discovered that the problem is worse than the press release indicates:

You are vulnerable even if you decline the MediaMax license agreement. Simply inserting a MediaMax-bearing CD into your PC paves the way for an attacker to come along and set a booby-trap. The trap will be sprung the next time you insert such a disc.
SonyBMG has released a patch that purports to fix the problem. However, our tests show that the patch is insecure. It turns out that there is a way an adversary can booby-trap the MediaMax files so that hostile software is run automatically when you install and run the MediaMax patch.
The previously released MediaMax uninstaller is also insecure in the same way, allowing an adversary to booby-trap files so that hostile software is run automatically when you try to use the uninstaller.

(These attacks are similar to the exploit described in iSEC’s report, but they involve a different modification to the MediaMax files.)

And their summary of the flaw…

As we’ve written before, the first time you insert a MediaMax-bearing CD into your Windows computer (assuming you have Windows autorun enabled, as most people do), MediaMax installs some software on your computer. Once this initial software is on your computer, you are vulnerable to the new attack. The gist of the problem is that MediaMax installs itself in a directory that anyone is allowed to modify, even users who otherwise run with heavily restricted security permissions. Any program that comes along can modify your MediaMax files, booby-trapping the files by inserting hostile software that will be run automatically the next time you insert a MediaMax-bearing CD into your computer. And because MediaMax is run with full administrator privileges, the hostile program gets to run with full privileges, allowing it to inflict any mischief it likes on your PC.

Further they point out that the problems with MediaMax are JUST as bad as those with XCP and MediaMax protected discs should be recalled as well.

–update 12/8/05 1:57PM EST–

freedom-to-tinker talks today on this issue again. The problems with the DRM software is really from design straight through to implementation. Sony needs to recall their MediaMax discs too. The software installs whether or not you accept the terms and conditions.

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