WebEx Downloader ActiveX Control and WebEx Downloader Java before 2.1.0.0 do not validate downloaded components, which allows remote attackers to execute arbitrary code via a website that activates the GpcUrlRoot and GpcIniFileName ActiveX controls to cause the client to download a DLL file.
https://exchange.xforce.ibmcloud.com/vulnerabilities/24370
http://xforce.iss.net/xforce/alerts/id/226
http://www.zerodayinitiative.com/advisories/ZDI-06-021.html
http://www.webex.com/lp/security/ActiveAdv.html?TrackID=123456
http://www.vupen.com/english/advisories/2006/2688
http://www.securityfocus.com/bid/18860
http://www.securityfocus.com/archive/1/439496/100/0/threaded