Three articles of interest on the new WiFi KRACK—
This is not a crypto bug but a protocol bug (a pretty obvious and trivial protocol bug). When a client connects to the network, the access-point will at some point send a random “key” data to use for encryption. Because this packet may be lost in transmission, it can be repeated many times. What the hacker does is just repeatedly sends this packet, potentially hours later. Each time it does so, it resets the “keystream” back to the starting conditions. The obvious patch that device vendors will make is to only accept the first such packet it receives, ignore all the duplicates. —Robert Graham @Errata Security
So this is essentially a replay attack—something that is not taken seriously enough in the security world, by and large.
Researchers this week published information about a newfound, serious weakness in WPA2 — the security standard that protects all modern Wi-Fi networks. What follows is a short rundown on what exactly is at stake here, who’s most at-risk from this vulnerability, and what organizations and individuals can do about it. —Krebs on Security
And, finally, an article on protecting your network from KRACK—
Wi-Fi is merely the first link in a long chain of communication happening over channels that we should not trust. If I were to guess, the Wi-Fi router you’re using has probably not received a security update since the day it got put together. Worse, it probably came with default or easily guessable administrative credentials that were never changed. Unless you set up and configured that router yourself and you can remember the last time you updated its firmware, you should assume that it is now controlled by someone else and cannot be trusted. —Konstantin Ryabitsev @Linux.com