Disk Management in Apple Mac OS X before 10.8.4 does not properly authenticate attempts to disable FileVault, which allows local users to cause a denial of service (loss of encryption functionality) via an unspecified command line.
Apple Security Advisory 2013-06-04-1 - OS X Mountain Lion version 10.8.4 and Security Update 2013-002 is now available and addresses over 30 security issues.