iDefense Security Advisory 02.23.10
http://labs.idefense.com/intelligence/vulnerabilities/
Feb 23, 2010

I. BACKGROUND

The getPlus Downloader is an application download and installation
manager, distributed in the form of an ActiveX control. This control is
used by Adobe Systems Inc. to install Adobe Reader through the Adobe
website when Internet Explorer is used. Part of the functionality of
the getPlus Downloader is to download and execute applications from
preconfigured sites; in the case of Adobe, from adobe.com and its
subdomains. For more information, see the vendor's site found at the
following link.

http://www.nosltd.com/index.php?option=com_content&task=view&id=38&Itemid=26

II. DESCRIPTION

Remote exploitation of an input validation vulnerability in NOS
Microsystems Ltd.'s getPlus Download Manager, as used by Adobe and
potentially other vendors, could allow an attacker to execute arbitrary
code with the privileges of the current user.

The vulnerability exists due to improper validation of the domain used
to download and execute applications from. The vulnerable code always
assumes that the domain being validated is a subdomain, which can lead
to a logic error when comparing the valid domain and the requested
domain.

III. ANALYSIS

Exploitation of this vulnerability results in the execution of arbitrary
code with the privileges of the user viewing the web page. To exploit
this vulnerability, a targeted user must load a malicious webpage
created by an attacker. An attacker typically accomplishes this via
social engineering or injecting content into compromised, trusted
sites. After the user visits the malicious web page, no further user
interaction is needed.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in getPlus
version 1.5.2.35 as distributed by Adobe. The Adobe Download Manager on
Windows (prior to February 23, 2010) has been confirmed vulnerable by
Adobe.

V. WORKAROUND

Setting the killbit for CLSID 'CF40ACC5-E1BB-4aff-AC72-04C2F616BCA7'
will prevent this control from loading in Internet Explorer.

VI. VENDOR RESPONSE

Adobe Systems Inc. has released a solution which addresses this issue.
Information about downloadable vendor updates can be found by clicking
on the URLs shown.
http://www.adobe.com/support/security/bulletins/apsb10-08.html

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2010-0189 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

06/09/2009  Initial Vendor Notification
06/09/2009  Initial Vendor Reply
02/23/2010  Coordinated Public Disclosure

IX. CREDIT

This vulnerability was reported to iDefense by Yorick Koster.

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X. LEGAL NOTICES

Copyright © 2010 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
of the information constitutes acceptance for use in an AS IS condition.
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