source: http://www.securityfocus.com/bid/13626/info

Yahoo! Messenger is prone to a denial-of-service vulnerability because the application fails to handle exceptional conditions.

A remote user can cause Yahoo! Messenger to disconnect through malicious emails or web pages.

This issue is reported to affect Yahoo! Messenger versions 5.x to 6.0 Windows; other versions on other operating systems may also be affected. 

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