WPA2 Security Flaw Puts Almost Every Wi-Fi Device at Risk of Hijack, Eavesdropping (zdnet.com)

A security protocol at the heart of most modern Wi-Fi devices, including computers, phones, and routers, has been broken, putting almost every wireless-enabled device at risk of attack. From a report: The bug, known as "KRACK" for Key Reinstallation Attack, exposes a fundamental flaw in WPA2, a common protocol used in securing most modern wireless networks. Mathy Vanhoef, a computer security academic, who found the flaw, said the weakness lies in the protocol's four-way handshake, which securely allows new devices with a pre-shared password to join the network. That weakness can, at its worst, allow an attacker to decrypt network traffic from a WPA2-enabled device, hijack connections, and inject content into the traffic stream. In other words: hackers can eavesdrop on your network traffic. The bug represents a complete breakdown of the WPA2 protocol, for both personal and enterprise devices -- putting every supported device at risk. "If your device supports Wi-Fi, it is most likely affected," said Vanhoef, on his website. News of the vulnerability was later confirmed on Monday by US Homeland Security's cyber-emergency unit US-CERT, which about two months ago had confidentially warned vendors and experts of the bug, ZDNet has learned.

Comments

Finally!

[khandom08]

Public announcement from Mathy Vanhoef is https://www.krackattacks.com/ and his research paper can be found https://papers.mathyvanhoef.co....

So which is it?

[Solandri]

the weakness lies in the protocol's four-way handshake, which securely allows new devices with a pre-shared password to join the network. [...] The bug represents a complete breakdown of the WPA2 protocol, for both personal and enterprise devices

WPA2 enterprise doesn't use a pre-shared key. So which is it? Does the weakness lie with pre-shared key passwords? Or something else which also affects WPA2 enterprise?

Ah, here we go. The answer is "it's complicated." I'm reading through it right now, but as a PSA:

• Here's the original paper on the attack
• Here's CERT's page on the attack
• Here's ICASI's (mostly useless) page on the attack

In the future can we link to original source articles or responses by authoritative organizations, instead of trade rags?

TLDR; Replay packet 3

[complete loony]

Replay packet 3 in the 4 way handshake, and the client will encrypt two different payloads with the same key and nonce. A big mistake with most encryption methods.

Worse, linux wpa_supplicant nulls out the key memory but still processes the replayed packet, causing the client to use a known (zero) key.

Re:How serious is this? How exploitable is it?

[140Mandak262Jamuna]

Not remotely exploitable. So it is not going to infect like the heartbleed or shellshock

Need to build a device with the special software and come within range of a router to sniff the keys. Then can eaves drop on communication between router and client.

It will take a day at least to build it and then one has to come physically close.

Vulnerable places will be coffee shops, malls, airports etc. Stores that use wi-fi between cash registers and router would be the primary target. BTW Target had security cameras and cash registers talking to the same router using same passwords. If I remember it correctly.

Re:How serious is this? How exploitable is it?

[khandom08]

No it is an attack on both. Though it appears that patched clients would be safe while connected to an upatched AP.

Re:How serious is this? How exploitable is it?

[Junta]

And vice versa, a patched AP can prevent a client from breaking. One or the other side needs to prevent it, but either side by itself is sufficient.

Re:How serious is this? How exploitable is it?

[Junta]

Note that I would *hope* point of sale equipment and security equipment would use TLS regardless of the media. If that were the case, then the WPA2 weakness would not suddenly provide access to that material.

For a private laptop connecting to public wifi-hotspots, this attack is harder than just setting up another credible wifi hotspot. Any place where the wifi password is well known knowledge is never going to be rigorous security.

Re:What the fuck is Google going to do about Andro

[Streetlight]

I'm not sure older devices have the hardware capable of supporting Android 8.0.0, aka, Oreo. Even phones a couple of generation old would likely would become unacceptably slow with the newer OS. A huge majority of Android devices are not Nexus or Pixel devices and generally not updated by the carriers. Even older Nexus devices are not guaranteed security updates by Google.

The best thing might be for Google to provide appropriate security patch software for WPA2 for all versions of Android to carriers but it's likely they would never reach customer phones.

Re:What the fuck is Google going to do about Andro

[squiggleslash]

The telcos have absolutely nothing to do with updates for Android phones, with the exceptions of those that they themselves have branded. It's the manufacturers who are responsible. Your comments were sort-of true for the previous generation of feature phones, but Android devices aren't something telcos have control over.

The problem here is that manufacturers have few incentives, apparently, to keep Android devices up to date.