Risk: High
Apple has patched a QuickTime security flaw that was first identified in November 2007.
The most critical vulnerability lies in QuickTime's implementation of the Real Time Streaming Protocol (RTSP), used to play audio and video over the Internet. Attackers may expolit the flaw by tricking users to click on a link so that they are then able to install malicious software.
Although these attacks are targeted at Windows-based systems, Mac OS X users could also be at risk. Apple has issued patches for both Windows and Mac OS X users.
Apple has also issued patches for a flaw in the QuickTime Media Link (QTL) file format used by the media player and for multiple bugs in the way that QuickTime handles Adobe's Flash media format.