An ActiveX control (Messenger.UIAutomation.1) in Windows Messenger 4.7 and 5.1 is marked as safe-for-scripting, which allows remote attackers to control the Messenger application, and "change state," obtain contact information, and establish audio or video connections without notification via unknown vectors.
A remote illegal access vulnerability exists in Microsoft Windows Live Messenger. A vicious attacker can control the Live Messenger via constructing a malicious web page.