Macrovision InstallShield Update Service ActiveX Unsafe Method Vulnerability

iDefense Security Advisory 10.31.07
http://labs.idefense.com/intelligence/vulnerabilities/
Oct 31, 2007

I. BACKGROUND

MacroVision InstallShield is an installer solution utilized by many
software vendors in order to ensure that their products are delivered
and setup properly on the end-user systems. InstallSheild includes
support for an optional component called the "Update Service". This
service allows vendors to notify clients of product patches and
updates, and allow them to be easily installed. More information on
this product is available on the vendor's site at the following URL.

http://www.macrovision.com/products/installation/installshield.htm

II. DESCRIPTION

Remote exploitation of an unsafe method vulnerability in Macrovision
InstallShield Update Service allows attackers to execute arbitrary code
with the privileges of the currently logged-in user.

The Update Service is implemented as an ActiveX control with the
following properties:

  CLSID: E9880553-B8A7-4960-A668-95C68BED571E
  File: C:\Windows\Downloaded Files\isusweb.dll
  Version: 5.01.100.47363, and 6.0.100.60146

This control is marked "safe for scripting". Several methods within this
control can be utilized by attackers to download and launch arbitrary
executables.

III. ANALYSIS

Exploitation allows attackers to execute arbitrary code with the
privileges of the currently logged-in user. In order for exploitation
to occur, users would be required to have a vulnerable version of the
software installed and be lured to a malicious site. Even though the
update control does display an interface, no additional interaction is
required in order for exploitation to occur.

Since this control is marked "safe for scripting", it can be launched
from a web page without warning dialogs. While it is possible for an
alert user to determine what is occurring and cancel the installation,
the window of opportunity is small and based solely upon the time
required for the system to complete the download.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in versions
5.01.100.47363, and 6.0.100.60146 of Macrovision InstallShield Update
Service. Previous versions are also suspected to be vulnerable.

This component is known to be distributed with Macrovision's
InstallShield 2008 application as well as their FlexNet SDK. Since the
component is designed to be utilized by 3rd party vendors, it is
believed to be widely distributed by a diverse range of products.

V. WORKAROUND

Administrators can set the kill-bit for the vulnerable ActiveX control
with the following .reg file. This will prevent the control from
loading within Internet Explorer.

  Windows Registry Editor Version 5.00
 
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX
Compatibility\{E9880553-B8A7-4960-A668-95C68BED571E}]
  "Compatibility Flags"=dword:00000400

VI. VENDOR RESPONSE

Macrovision has addressed this vulnerability by releasing updated
versions of their FlexNet and InstallShield products. They report that
the new versions are no longer marked as "safe for scripting". For more
information, consult the following URL.

http://www.macrovision.com/promolanding/7660.htm

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2007-5660 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

09/24/2007  Initial vendor notification
09/24/2007  Initial vendor response
10/31/2007  Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright © 2007 iDefense, Inc.

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
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