Apple released earlier this week a Security Update (2004-10-27) for systems running MacOS X version 10.3. According to ComputerWorld, the patch that was also made available through the Software Update system preference pane delivers "a number of security enhancements and is recommended for all Macintosh users":
The release includes an updated version of Apple Remote Desktop v1.2.4 running on Mac OS X v10.3. The problem only affects Macs running Mac OS X v10.3 and Apple Remote Desktop v1.2.4, where:
* A user on the client system has been enabled with the Open and quit applications privilege;
* The username and password of the Apple Remote Desktop user is known;
* Fast user switching has been enabled;
* A user is logged in, and loginwindow is active via Fast User Switching.