The Vista sidebar is a desktop extension that allows the user to keep a number of "gadgets", which are mini-applications, running in constant view on the desktop. Vista provides a number of default gadgets, such as a calendar, a weather tool, and an RSS feed reader.
RSS feeds allow a content provider, such as a website, to let others receive a stream of "headlines" describing content on the provider's site. The feeds are often updated frequently, and allow a user to receive information from a site without having to visit it. For example, a user may subscribe to a news feed that updates every hour with the headlines of top news stories. In order to subscribe to a feed, a user needs a feed reader. Modern browsers, such as Internet Explorer, provide a feed reader within the browser.
For more information about the Vista Sidebar and Gadgets please see the following URL.
Remote exploitation of a Cross Site Scripting (XSS) vulnerability in the Windows Vista Sidebar RSS Gadget allows an attacker to execute arbitrary code with the privileges of the logged in user.
The RSS gadget runs by default, but does not display any feeds unless a user subscribes to them. As such, a user must be receiving data from a malicious feed in order to be attacked.
In the most common scenario, this requires some form of social engineering to convince a user to subscribe to a malicious feed. There is no way to add a feed by simply clicking a link. The user must click the 'Subscribe to this feed' button displayed when visiting a feed in Internet Explorer. After adding the feed, exploitation will occur once the gadget attempts to display the feed.
Another attack vector that requires significantly less social engineering requires an attacker control a trusted feed. If an attacker can find some way to inject data into a trusted feed then they will be able to exploit any subscribers to the feed.
iDefense has confirmed the existence of this vulnerability in Microsoft Windows Vista Business. Other versions are suspected to be vulnerable.
iDefense is currently unaware of any workarounds for this issue.
Microsoft has addressed this vulnerability within MS07-048. For more information, consult their bulletin at the following URL.
The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-3033 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems.
03/21/2007 Initial vendor notification
03/21/2007 Initial vendor response
08/14/2007 Coordinated public disclosure
This vulnerability was reported to iDefense by Aviv Raff.
Get paid for vulnerability research
Free tools, research and upcoming events
Copyright © 2007 Verisign, Inc.
Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDefense. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please e-mail customer service for permission.
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. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.