The helper application in Cisco AnyConnect Secure Mobility Client (formerly AnyConnect VPN Client) before 2.3.185 on Windows, and on Windows Mobile, downloads a client executable file (vpndownloader.exe) without verifying its authenticity, which allows remote attackers to execute arbitrary code via the url property to a certain ActiveX control in vpnweb.ocx, aka Bug ID CSCsy00904.
https://exchange.xforce.ibmcloud.com/vulnerabilities/67739
http://www.securitytracker.com/id?1025591
http://www.kb.cert.org/vuls/id/490097
http://www.cisco.com/en/US/products/products_security_advisory09186a0080b80123.shtml
http://securityreason.com/securityalert/8272
http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=909