http://www.macrumors.com/2008/06/09/quicktime-7-5-released/
Apple has released QuickTime 7.5, now available via Software Update.
Quote:
QuickTime 7.5 improves application compatibility and addresses security issues.
This release is recommended for all QuickTime 7 users.
For detailed information on the security content of this update, please visit this website: http://www.info.apple.com/kbnum/n61798.