MacOS X is not Invulnerable

Apple has fixed a nasty longstanding bug. This bug seems to enable user space programs to overwrite arbitrary locations in the kernel memory. The impact of this depends on how easy it is to guess the location of the target. A technique called Address Space Layout Randomization is expected to help here. Attackers need to guess the location of target variables or code for many computers in order to create a worm or rootkit that spreads using this vulnerability. However, it seems that the kernel memory is not randomized so all macs prior to the latest version of Leopard are vulnerable.