A chink in the armor of WPA/WPA2 WiFi security

Looks like your WiFi might not be quite as secure as you thought it was. A paper recently published by [Stefan Viehböck] details a security flaw in the supposedly robust WPA/WPA2 WiFi security protocol. It’s not actually that protocol which is the culprit, but an in-built feature called Wi-Fi Protected Setup. This is an additional security protocol that allows you to easily setup network devices like printers without the need to give them the WPA passphrase. [Stephan’s] proof-of-concept allows him to get the WPS pin in 4-10 hours using brute force. Once an attacker has that pin, they can immediately get the WPA passphrase with it. This works even if the passphrase is frequently changed.

Apparently, most WiFi access points not only offer WPS, but have it enabled by default. To further muck up the situation, some hardware settings dashboards offer a disable switch that doesn’t actually do anything!

It looks like [Stephan] wasn’t the only one working on this exploit. [Craig] wrote in to let us know he’s already released software to exploit the hole.

D-Link router captcha broken

d-link

We reported last week that D-Link was adding captchas to their routers to prevent automated login by malware. Unsurprisingly, it doesn’t work all time. The team from SourceSec grabbed the new firmware and began poking at it. They found that certain pages don’t require the authentication to be passed for access. One of these is WPS activation. WPS lets you do push button WPA configuration. Once activated, any nearby client can request the WPA key using a tool like WPSpy. Only user level credentials are needed to pull this off, so changing just the admin password won’t prevent it.

[photo: schoschie]

New WPA TKIP attack

wifibox

[Martin Beck] and [Erik Tews] have just released a paper covering an improved attack against WEP and a brand new attack against WPA(PDF). For the WEP half, they offer a nice overview of attacks up to this point and the optimizations they made to reduce the number of packets needed to approximately 25K. The only serious threat to WPA so far has been the coWPAtty dictionary attack. This new attack lets you decrypt the last 12 bytes of a WPA packet’s plaintext and then generate arbitrary packets to send to the client. While it doesn’t recover the WPA key, the attacker is still able to send packets directly to the machine they’re attacking and could potentially read back the response via an outbound connection to the internet.

[photo: niallkennedy]

[via SANS]