Airport Extreme Update 2007-001 is available vis Software Update and also as a 6.5MB standalone installer.
More info and download link here.
Gregg Keizer reports for InformationWeek, “The vulnerability in Apple’s Mac OS X AirPort Extreme driver was made public in late November 2006 as the final entry in the “Month of Kernel Bugs” project run by the researcher HD Moore.”
Full article here.
Related article:
Apple AirPort Utility 1.0 screenshots, 802.11n AirPort Extreme Base Station manuals – January 26, 2007