oss-sec mailing list archives

Re: Vulnerabilities reported in ClamAV 0.96.4


From: Vincent Danen <vdanen () redhat com>
Date: Wed, 21 Mar 2012 12:02:12 -0600

* [2012-03-21 13:41:44 -0400] Matt Watchinski wrote:

Yup goes somewhere useful.

We don't have anymore information than you, but they are loaded in our
bugtracker for investigation.  From our understanding the researcher did test
0.96.4, and not 0.97.4.

Thanks Matt, and Edwin, for the prompt responses.  Hopefully the
researcher will respond as promptly (it would definitely be good to know
whether or not the current 0.97.4 is still vulnerable).

Thanks again (especially for the bugzilla links in Edwin's message).

On Wed, Mar 21, 2012 at 12:51 PM, Vincent Danen <vdanen () redhat com> wrote:

   Hopefully security@ for ClamAV goes somewhere useful (I don't feel like
   opening a bugzilla account there just to ask this).

   Saw a bunch of CVEs come through for various anti-virus products, five
   of which are reportedly applicable for ClamAV 0.96.4.  I'm wondering a)
   if the upstream folks know about these and b) whether or not the report
   has a typo in the version, since 0.97.4 is the latest upstream version?

   http://www.securityfocus.com/archive/1/522005

   Indicates that CVE-2012-1419, CVE-2012-1443, CVE-2012-1457,
   CVE-2012-1458, and CVE-2012-1459 affect ClamAV 0.96.4.  There isn't much
   more information though.  Cutting-n-pasting from the report:

   1. Specially crafted infected POSIX TAR files with "[aliases]" as first
   9 bytes evades detection. (CVE-2012-1419)

   [...]

   25. Infected RAR files with initial two bytes set to 'MZ' can be fixed
   by the user and correctly extracted. Such a file evades detection.
   (CVE-2012-1443)

   [...]

   39. If the length field in the header of a file with test EICAR virus
   included into a TAR archive is set to be greater than the archive's
   total length (1,000,000+original length in our experiments), the
   antivirus declares the file to be clean but virus gets extracted
   correctly by the GNU tar program. (CVE-2012-1457)

   40. A Windows Compiled HTML Help (CHM) file is a set of HTML files,
   scripts, and images compressed using the LZX algorithm.  For faster
   random accesses, the algorithm is reset at intervals instead of
   compressing the entire file as a single stream. The length of each
   interval is specified in the LZXC header.

   If an infected CHM file's header modified so that the reset interval is
   lower than in the original file, the antivirus declares the file to be
   clean. But the Windows CHM viewer hh.exe correctly decompresses the
   infected content located before the tampered header. (CVE-2012-1458)

   41. In a POSIX TAR archive, each member file has a 512-byte header
   protected by a simple checksum. Every header also contains a file length
   field, which is used by the extractor to locate the next header in the
   archive.

   If a TAR archive contains two files: the first one is clean, while the
   second is infected with test EICAR virus - and it is modified such that
   the length field in the header of the first, clean file to point into
   the middle of the header of the second, infected file. The antivirus
   declares the file to be clean but virus gets extracted correctly by the
   GNU tar program. (CVE-2012-1459)

   --
   Vincent Danen / Red Hat Security Response Team




--
Matthew Watchinski
V.P. Vulnerability Research (VRT)
Sourcefire, Inc.
Office: 410-423-1928
http://vrt-blog.snort.org && http://www.snort.org/vrt/

--
Vincent Danen / Red Hat Security Response Team

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