Cross-site scripting (XSS) vulnerability in the Web Client in VMware vCenter Server 5.1 before update 3d, 5.5 before update 3d, and 6.0 before update 2 on Windows allows remote attackers to inject arbitrary web script or HTML via the flashvars parameter.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.