fdesetup in Apple OS X before 10.10 does not properly display the encryption status in between a setting-update action and a reboot action, which might make it easier for physically proximate attackers to obtain cleartext data by leveraging ignorance of the reboot requirement.
https://support.apple.com/kb/HT6535
https://exchange.xforce.ibmcloud.com/vulnerabilities/97637
http://www.securitytracker.com/id/1031063
http://www.securityfocus.com/bid/70632
http://archives.neohapsis.com/archives/bugtraq/2014-10/0101.html