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Re: CVE Request -- EncFS / fuse-encfs [three ids] -- Multiple Vulnerabilities in EncFS


From: Josh Bressers <bressers () redhat com>
Date: Tue, 7 Sep 2010 15:05:38 -0400 (EDT)

Here goes:

CVE-2010-3073 encfs Only 32 bit of file IV used
CVE-2010-3074 encfs Watermarking attack
CVE-2010-3075 encfs Last block with single byte is insecure"

Thanks

-- 
    JB


----- "Jan Lieskovsky" <jlieskov () redhat com> wrote:

Hello Steve, vendors,

   Micha Riser reported:
   [A]
http://archives.neohapsis.com/archives/fulldisclosure/2010-08/0316.html

three security flaws in EncFS encrypted filesystem (more from [A]):

"A security analysis of EncFS has revealed multiple vulnerabilities:
(1) Only 32 bit of file IV used
(2) Watermarking attack
(3) Last block with single byte is insecure"

References:
   [B] http://www.arg0.net/encfs
   [C] http://bugs.gentoo.org/show_bug.cgi?id=335938
   [D]
http://archives.neohapsis.com/archives/fulldisclosure/2010-08/att-0316/watermark-attack-encfs.tar.gz
   [E] https://bugzilla.redhat.com/show_bug.cgi?id=630460


Solutions / patches information:
================================

* for issue (1) -- seems it wasn't fixed / isn't possible to
   fix without breaking backward compatibility. More from [B]:

   "The old IV setup is kept for backwards compatibility."

* for issue (2) -- EncFS upstream has released a fix for the issue:
   [F] http://code.google.com/p/encfs/source/detail?r=59

Valient, could you please confirm, the above referenced [F] patch,
is the correct one to address the watermarking attack issue?

* for issue (3) -- not sure about patch status (included in [F] too?)

Steve, could you allocate CVE ids for these flaws?

Thanks && Regards, Jan.
--
Jan iankko Lieskovsky / Red Hat Security Response Team


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