The Monday-released update version 10.6.2 of Apple's Mac OS X Snow Leopard has not only fixed a host of security issues, but has also enhanced the overall performance of the operating system.

The Security Update 2009-006, which describes the fixes for Mac OS X 10.6.2, notes that as many as 40 security vulnerabilities have been addressed by the latest update - most of the vulnerabilities pertain to the open source components of Mac OS X, like Apache or Subversion.

Among the important stability and usability issues that have been fixed, including 14 OS problems, include the hitch related to deletion of users' data while using a Guest account login; and an issue that brought about the users' unexpected logging out from their systems; and a Spotlight search problem that prevented the viewing of Exchange contacts.

In addition, the other flaws addressed by the update include those in QuickTime and CoreMedia - these flaws allowed remote code execution via the exploitation of the maliciously-crafted media files.

Furthermore, with Microsoft Vulnerability Research and IOACTIVE security researcher Dan Kaminsky having identified a weakness in the MD2 hash algorithm, Apple has disabled support for X.509 certificates with MD2 encryption for uses except trusted root certificates. 

Apple said that the restriction on the use of X.509 certificates is essentially "a proactive change to protect users in advance of improved attacks against the MD2 hash algorithm."