VMware vSphere Client 4.0, 4.1, 5.0 before Update 3, and 5.1 before Update 2 does not properly validate updates to Client files, which allows remote attackers to trigger the downloading and execution of an arbitrary program via unspecified vectors.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2014-1290
http://www.vmware.com/security/advisories/VMSA-2014-0003.html