Vulnerability Note VU#983731

eBay Enhanced Picture Uploader ActiveX control vulnerable to arbitrary command execution

Overview

The eBay Enhanced Picture Uploader ActiveX control allows arbitrary commands to be executed.

I. Description

The eBay Enhanced Picture Uploader ActiveX control is used by the eBay web site to give Internet Explorer users additional functionality when uploading pictures to an auction. This ActiveX control is provided by the file EPUWALcontrol.dll. If an attacker provides a specially-crafted PictureUrls property or initialization parameter, the ActiveX control will execute the commands that are specified.

II. Impact

By convincing a user to view a specially crafted HTML document (e.g., a web page or an HTML email message or attachment), an attacker may be able to execute arbitrary commands with the privileges of the user.

III. Solution

Apply an update

This update is addressed in version 1.0.27 of the Ebay Enhanced Picture Control software. This update can be obtained by visiting the eBay web site, creating a new auction and uploading images with the Internet Explorer web browser. This control is also disabled in Internet Explorer with the update for Microsoft Security Advisory (969898). Please see the eBay security center announcement for additional details.

Please also consider the following workarounds:

Disable the eBay Enhanced Picture Uploader ActiveX control in Internet Explorer

The vulnerable ActiveX control can be disabled in Internet Explorer by setting the kill bit for the following CLSIDs:

{4C39376E-FA9D-4349-BACC-D305C1750EF3}
{C3EB1670-84E0-4EDA-B570-0B51AAE81679}

More information about how to set the kill bit is available in Microsoft Support Document 240797. Alternatively, the following text can be saved as a .REG file and imported to set the kill bit for this control:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESOFTWAREMicrosoftInternet ExplorerActiveX Compatibility{4C39376E-FA9D-4349-BACC-D305C1750EF3}]
"Compatibility Flags"=dword:00000400

[HKEY_LOCAL_MACHINESOFTWAREMicrosoftInternet ExplorerActiveX Compatibility{C3EB1670-84E0-4EDA-B570-0B51AAE81679}]
"Compatibility Flags"=dword:00000400

Disable ActiveX

Disabling ActiveX controls in the Internet Zone (or any zone used by an attacker) appears to prevent exploitation of this and other ActiveX vulnerabilities. Instructions for disabling ActiveX in the Internet Zone can be found in the "Securing Your Web Browser" document.

Systems Affected

Vendor	Status	Date Notified	Date Updated
eBay	Vulnerable	2008-08-27	2009-06-09

References

http://www.cert.org/tech_tips/securing_browser/#Internet_Explorer
http://pages.ebay.com/securitycenter/activex/index.html
http://www.microsoft.com/technet/security/advisory/969898.mspx
http://support.microsoft.com/kb/240797

Credit

Thanks to Chris Weber of Casaba Security for reporting this vulnerability.

This document was written by Will Dormann.

Other Information

Date Public:	2009-06-09
Date First Published:	2009-06-09
Date Last Updated:	2009-06-09
CERT Advisory:
CVE-ID(s):	CVE-2008-2475
NVD-ID(s):	CVE-2008-2475
US-CERT Technical Alerts:
Metric:	7.36
Document Revision:	9