Security Update 2005-001 for Mac OS X
Apple has posted Security Update 2005-001 for Mac OS X in Software Update:
Security Update 2005-001 delivers a number of security enhancements and is recommended for all Macintosh users. This update includes the following components:
For detailed information on this Update, please visit this website: http://www.info.apple.com/kbnum/n61798
Apple appears to have started using a numbering scheme for their security updates, rather than relying on date of release as they have done in the past.