At 21:00 GMT today, Apple released the Mac OS X 10.3.4 Update. The nice thing about this update is, that it fixes the telnet security hole everyone was talking about lately. I don’t know if other URL-related security issues were also fixed, I’ll check it out later.
Update: All security issues described here are still present in OS X 10.3.4. Further reading about the URL vulnerabilities is available here.