Cracking WPA with Cowpatty 4.5
A lot has changed since I last talked about WPA Cracking on Hak5. Specifically Joshua Wright, author of CowPatty has released a new version that dramatically changes the way one thinks about cracking WPA and WPA2 TKIP keys.
The most notable new feature in Cowpatty 4.5 is the “-2″ option, which only requires the first two frames of the 4-way handshake to start attacking.
By removing the need for the third and fourth frames of the handshake, an attacker is now more likely to successfully crack WPA keys when channel hopping. Furthermore, the lack of the third and fourth frame opens up a world of possabilities when it comes to trapping targets with rogue access points, or “honey pots”.
An example scenario illustrated on Wright’s blog details how an attacker may pose as a victim’s corporate wireless access point. Since it doesn’t matter if the target associates with the honey pot, anything from hostap to a spare WPA supporting access point with a bogus key will due.
Of course this has our friend Robin Wood pondering a Jasager plugin. Pineapples anyone?
As for carrying out the attack it’s pretty straight forward. I BackTrack as my hacking OS of choice coupled with an eee PC or Acer Aspire One. When it comes to Wireless I’m a big fan of the ALFA AWUS036H 500mW USB Wireless Adapter.
Other tools needed to carry out the attack include WPA tables like these SSID specific Cowpatty WPA Tables from Offensive Security and the Aircrack-ng suite.
The commands are pretty straight forward and well highlighted in the episode. There are a number of ways to go about this so if you’ve got another method you’d like to share with me, questions about this, or suggestions for future topics drop me a line. darren[at]hak5=dot=org.