Apple has released a security update for Mac OSX and MacOSX server that fixes a logic issue related to the dynamic DNS update message. The flaw allowed allow an assertion to be tiggered resulting in the BIND service to be disrupted. All masters servers of zones could be exploited in this manner no matter if they accepted updates by a maliciously crafted update. The update is aviable via Softwre update or via http://support.apple.com/downloads/ and is recomended to be installed right away.