Wednesday, December 07, 2005

Sony rootkit again

*Sigh* OK, this is getting really tedious:

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.)

Because of these problems, we recommend for now that if you have a Windows PC, you (1) do not use the MediaMax patch, (2) do not use the previously released MediaMax uninstaller, and (3) do not insert a MediaMax-bearing CD into your PC.

We have notified SonyBMG and MediaMax about these problems. We assume they will develop a new uninstaller that safely rids users’ computers of the MediaMax software once and for all.

The consequences of this problem are just as bad as those of the XCP rootkit whose discovery by Mark Russinovich started SonyBMG’s woes. This problem, like the rootkit, allows any program on the system to launch a serious security attack that would normally be available only to fully trusted programs.

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