Buffer overflow in the Yahoo! Audio Conferencing (aka Voice Chat) ActiveX control before 1,0,0,45 allows remote attackers to cause a denial of service and possibly execute arbitrary code via a URL with a long hostname to Yahoo! Messenger or Yahoo! Chat.
https://exchange.xforce.ibmcloud.com/vulnerabilities/12130
http://www.securityfocus.com/bid/7561
http://www.securityfocus.com/archive/1/323439
http://www.kb.cert.org/vuls/id/272644