Apple has issued a small security update for all major versions of Mac OS X still in use, including OS X Mountain Lion, Snow Leopard, and Lion.
Release notes are extremely brief, noting simply that the update is “recommended for all users and improves the security of OS X.” There is some indication that the update may address a potential security issue with QuickTime movie player, though that remains unclear at the moment. Users have noticed that the update for OS X 10.8 and 10.7 is quite small, where as for 10.6 it is more sizable.
Everyone can download Security Update 2013-003 from Software Update, accessible via the Apple menu, or directly through the App Store. Installing the update requires a reboot to complete.