Yuck

This wasn’t what I wanted to wake up to this morning:
The security protocol used to protect the vast majority of wifi connections has been broken, potentially exposing wireless internet traffic to malicious eavesdroppers and attacks, according to the researcher who discovered the weakness.
This one is very bad folks; I’ve read the paper and related CVEs.
The attack results from a problem in how keys are negotiated between a WiFi router and client. It’s supposed to be impossible (with a proper key negotiation) to force a “favored” key or re-use of a temporal key. This is enforced by using what is called a nonce; a sequence of random numbers that are used just once (“Number ONCE”).
Unfortunately the standard itself left open a way to force the “other end” to reuse a nonce. This is very bad because you can use this sort of attack to trick the other end into installing a key you know; such as “all zeros.” Once you’ve done that you can decrypt anything the victim sends because you have the key, and once broken you also have access to all future key renegotiations as long as you remain “in-range”.
Encryption relies on not just one but two things being unknown: The key and the content. If someone can force the key (including the nonce) to be reused with known content then you’re in big trouble.

This post was published at Market-Ticker on 2017-10-16.