Microsoft Outlook 2002 and 2003 allows user-assisted remote attackers to execute arbitrary code via a malformed VEVENT record in an .iCal meeting request or ICS file.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A516
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2007/ms07-003
http://www.vupen.com/english/advisories/2007/0104
http://www.us-cert.gov/cas/techalerts/TA07-009A.html
http://www.securityfocus.com/bid/21931
http://www.securityfocus.com/archive/1/457274/100/0/threaded
http://www.kb.cert.org/vuls/id/476900