Fresh on the heels of yesterday's huge Apple Security Update 2008-0002, today Apple released 2008-03-19 firmware update for the current (and pre-gigabit) Airport Extreme Base Stations.

AirPort Extreme Base Station with 802.11n*
CVE-ID:  CVE-2008-1012
Available for:  AirPort Extreme Base Station with 802.11n*
Impact:  A maliciously crafted AFP request may lead to a denial of
service
Description:  An input validation issue exists in the AirPort Extreme
Base Station's handling of AFP requests, which may cause file sharing
to become unresponsive. This update addresses the issue by performing
additional validation of AFP requests. This issue does not affect
Time Capsule or AirPort Express. The fix for this issue is available
in the following separate updates:
- - AirPort Extreme with 802.11n (Fast Ethernet) 7.3.1
- - AirPort Extreme with 802.11n (Gigabit Ethernet) 7.3.1
Credit to Alex deVries for reporting this issue.

More info here.  (Although, I think I posted the whole thing above...)

To update to the newest firmware, open Airport Utility that is in your Utilities Folder in Applications.  (If you are using a Mac, if you are using it for Windows, well, I don't know where it's at. ;)  It should automatically check for the newest update and prompt you.  It's a two click download and update. 

Joel Esler

http://www.joelesler.net