oss-sec mailing list archives

Re: CVE Request -- openvas-scanner -- Insecure temporary file use by generation of an OVAL system characteristics document, when ovaldi support enabled


From: Josh Bressers <bressers () redhat com>
Date: Fri, 9 Sep 2011 13:45:03 -0400 (EDT)

Let's go with one ID. I don't see a reason to split these.

Use CVE-2011-3351

Thanks.

-- 
    JB


----- Original Message -----
On Wednesday 07 Sep 2011 13:13:45 Jan Lieskovsky wrote:
Hello Josh, Steve, vendors,

   it was reported that the scanner module for the Open
   Vulnerability
Assessment System (OpenVAS) used insecure way for creation of a
temporary file, when generating OVAL system characteristics document
from the knowledge base data available, with the ovaldi integrated
tool
enabled. A local attacker could use this flaw to conduct symlink
attacks to overwrite arbitrary files on the system, accessible with
the
privileges of the user running the SLAD daemon and / or the ovaldi
OVAL
interpreter.


Whilst having a look at the code with regard to the recently reported
f-d
issue with OpenVAS, the handling of sc-out.xml in the very same
function also
looks insecure. It also doesn't appear to care about races either and
I'm
also curious as to whether you can control the contents at all (think
attacks
against the ovaldi XML parser). I would suggest that this code needs
properly
auditing or removing.

Unfortunately the interaction with sc-out.xml happens before
privileges are
dropped so the malicious activitity occurs as the openvas-scanner user
(normally root) rather than nobody as in the case of results.xml - The
call to
unlink referenced in the f-d email is actually a misnomer as it will
actually
only delete the file from /tmp and not whatever it may or may not have
pointed
to and the actual writing to the newly race created symlink actually
happens
within the ovaldi binary which is spawned as nobody AFAIK.

Josh/oss-security folk, can I get a CVE for both bugs please. Will we
need to
split out the two race conditions as separate CVE? The OpenVAS
advisory will
cover both the originally reported nobody case as well as the root
case
referenced above.

Tim
--
Tim Brown
<mailto:timb () openvas org>
<http://www.openvas.org/>


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