Apple has updated its QuickTime software, now at version 7.6.9, to fix vulnerabilities where a maliciously designed file could execute arbitrary code or lead to the application terminating.
As Apple describes in its knowledge base article:"Description: A heap buffer overflow exists in QuickTime's handling of JP2 images. Viewing a maliciously crafted JP2 image may lead to an unexpected application termination or arbitrary code execution. This issue is addressed through improved bounds checking. For Mac OS X v10.6 systems, this issue is addressed in Mac OS X v10.6.5. Credit to Nils of MWR … Read more