802.11b WEP Security Update...

August 22, 2001
by Brad Knowles
Columnist

I know it hasn't been long since my previous article on this subject (see "More on AirPort/IEEE 802.11b Security"), but I just found out about a tool that is publicly available which actually implements the attacks described in the paper by Fluhrer, Mantin and Shamir at <http://www.cs.umd.edu/~waa/class-pubs/rc4_ksaproc.ps> and <http://eyetap.org/~rguerra/toronto2001/rc4_ksaproc.pdf>, and discussed in the paper by Stubblefield, Ioannidis and Rubin at <http://www.cs.rice.edu/~astubble/wep/>.

This new tool is called "AirSnort", and you can read more about it in the Wired article "Wireless Networks in Big Trouble" at <http://www.wired.com/news/print/0,1294,46187,00.html>. Note that they also mention another tool called "WEPCrack", but which is considered to be "alpha quality software", as opposed to the "beta" of AirSnort that is now available.

Unfortunately, this program currently runs only under Linux (no port available for MacOS X, yet), and the cards it supports do not include the Apple AirPort (or the Lucent/Agere WaveLAN/Orinoco on which the Apple AirPort is based).

Anyway, in the span of just a few days, any illusions you ever had of being secure should now be eliminated.

If you use 802.11b wireless networking, you should consider yourself to be wide-open and ripe for all kinds of attack and abuse. That is, unless you put your 802.11b base station outside of a firewall, and the only traffic allowed across the firewall is to a secure Virtual Private Network (VPN) server that uses a more advanced protocol (e.g., based on IPSec, such as PGPnet).