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.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5995
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2008/ms08-050
http://www.vupen.com/english/advisories/2008/2354
http://www.us-cert.gov/cas/techalerts/TA08-225A.html
http://www.securitytracker.com/id?1020681
http://www.securityfocus.com/bid/30551
http://www.securityfocus.com/archive/1/495467/100/0/threaded