WindowServer in Apple OS X through 10.9.2 does not prevent session creation by a sandboxed application, which allows attackers to bypass the sandbox protection mechanism and execute arbitrary code via a crafted application.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2014-1392
http://archives.neohapsis.com/archives/bugtraq/2014-04/0134.html