The VPN downloader implementation in the WebLaunch feature in Cisco AnyConnect Secure Mobility Client 2.x before 2.5 MR6 on Windows, and 2.x before 2.5 MR6 and 3.x before 3.0 MR8 on Mac OS X and Linux, does not properly validate binaries that are received by the downloader process, which allows remote attackers to execute arbitrary code via vectors involving (1) ActiveX or (2) Java components, aka Bug ID CSCtw47523.