Many security problems have dogged Mac OS X for some time now, including flaws that could enable an attacker to crash or freeze the Apache 2 Web server, run software by utilizing Apple's Safari Web browser or expose the password store used by the network. There are also critical flaws in the Kerberos authentication system, as well as many other problems.
Apple have now released a fix for these problems. In fact, the fix released today plugs 15 security flaws. The patch is available for Mac OS X 10.3.5 and Mac OS X 10.3.4, and also fixes issues in Mac OS X 10.2.
Apple have traditionally been slow to release patches, but now it looks like both themselves and other companies such as Oracle will be following Microsoft's example and releasing almost as many updates as is usual for Open Source software.