CFPreferences in Apple OS X before 10.10 does not properly enforce the "require password after sleep or screen saver begins" setting, which makes it easier for physically proximate attackers to obtain access by leveraging an unattended workstation.
Apple Security Advisory 2014-10-16-1 - OS X Yosemite v10.10 is now available and addresses 802.1X, AFP file server, Apache, App Sandbox, and various other vulnerabilities.