Original URL: http://www.theregister.co.uk/2010/07/27/wpa2_security/

Wireless network security weakness to demo at DEFCON

Et tu, WPA2?

By John Leyden

Posted in Security, 27th July 2010 18:51 GMT

Security researchers have discovered security shortcomings in the WPA2 protocol that threaten the security of wireless networks, even if they are running up-to-date security software.

The hack involves generating arbitrary broadcast packets from a spoofed node that trick legitimate nodes in a targeted network into responding with queries that give away information about their secret keys. The traffic does not, of course, give away the private key directly, but it does provide enough clues for this information to be extracted by subsequent cryptanalysis and high-end number crunching.

The attack was discovered by wireless security experts at AirTight Networks, who found it was possible to spoof the MAC address of a kosher access point by adding just 10 lines of code to the open source Madwifi driver and running this software on a standard PC, H Security reports. However, for the attack to succeed, hackers already need to be internal, authorised users of targeted networks.

WPA2 (Wi-Fi Protected Access 2) is the strongest security algorithm for wireless network currently available. It's already widely used in enterprises and increasingly popular in Wi-Fi hotspots. WPA2 is the successor to the earlier WPA standard, which itself followed WEP (Wired Equivalent Privacy), an amateurish first stab at wireless security that was riddled with serious security holes and easy to break right from the start.

The comparatively minor security shortcomings of WPA2 – which are more at interested to cryptographic security researchers than would-be wireless hackers – stem from security holes in IEEE 802.11 standard rather than implementation bugs. Although not suitable for external hackers the security flaw does present plenty of scope for mischief, according to a pre-talk advisory from AirTight, chiefly as a potential way to spy on supposedly encrypted traffic or to plant malware.

Exploiting the vulnerability, an insider can bypass WPA2 private key encryption and authentication to sniff and decrypt data from other authorized users as well as scan their Wi-Fi devices for vulnerabilities, install malware and possibly compromise those Wi-Fi devices.

Sohail Ahmad, senior wireless security researcher for AirTight Networks, is due to demo his findings at the Black Hat and later DEFCON18 conferences in Las Vegas this week. ®