ActiveX Update

December 8, 2006

Do I need to update Yahoo! Messenger to the new version?

Yes, if you are using a version of Yahoo! Messenger obtained before March 13, 2007 on a Windows PC.

How do I get the Security Update?

You can download the latest version of Yahoo! Messenger from Select the typical install option during the install process.

What is the security issue?

Yahoo! recently identified a security issue, commonly referred to as a buffer overflow in an ActiveX control. This control is part of the Yahoo! services suite typically downloaded with the installer for Yahoo! Messenger.

How did Yahoo! learn of this?

Yahoo! has relationships with third-party security organizations and researchers.

What is the potential impact?

Some impacts of a buffer overflow might include being involuntarily logged out of a Chat and/or Messenger session, the crash of an application such as Internet Explorer, and in some instances, the introduction of executable code. For this specific issue, these impacts could only be possible if an attacker is successful in prompting someone to view malicious HTML code, most likely executed by getting a person to visit their web page. To our knowledge, there have been no known executable code exploits related to this issue.

Who is affected?

If your computer has installed Yahoo! Messenger before November 2, 2006, you should install the update.

Why do I have to install the update?

Installing the update helps protect against exploits of this issue that may be developed.

How long will it take?

The update should take no more than a few minutes, although the exact time depends on the speed of your Internet connection.

What if I don't install the update?

Each time you sign in to Yahoo! Messenger, you will be prompted to update. If you choose not to update and you have not updated via this page, the vulnerability will still exist.

I'm a technical user. What is the CLSID and exact version of the control that contains the fix?

The CLSID is AA218328-0EA8-4D70-8972-E987A9190FF4 and the version 2005.1.1.4 or above.