Key ReInstallation Attack, or KRAck Attack by Mathy Vanhoef


Key Reinstallation Attacks, or KRACKs (follow the link for the full article). The 3rd message of the 4 way handshake is mimicked by the attacker, forcing a client to reinstall the same encryption key over and over. This can be done because Access Points can re-transmit message 3 if they don’t receive an appropriate response, meaning that a client can also receive the message multiple times. It’s especially effective against anything using wpa_supplicant, such as Android Phones.

To counter this, I assume some kind of security patch or other will be released soon, but this could mean the replacement of WPA-2. Only now we have a lot more replacing to do than when other protocols were replaced, which means a lot of devices are still going to be using WPA-2.

Edit: Also, I’m sure you guys already know this (we are on after all) but please, protect your shit. Don’t do stupid stuff like make your online bank account password boobies12 and then save it in a cookie.

(Thomas) #2

boobs12? who the hell would use that. boobs69 is a much better choice.

(Hardeep Singh) #3

It doesn’t seem to be a router vulnerability. So no need for WPA3 I think. It is a client side vulnerability and routers need not to be patched.

Do you need WPA3?

Not really!

Ubuntu, Fedora, OpenBSD have already released patches. Other vendors will release soon considering the severity of the attack.

OpenBSD was notified of the vulnerability on 15 July 2017, before CERT/CC was involved in the coordination

Microtik also released an article recently: RouterOS NOT affected by WPA2 vulnerabilities

It’s been a long time actually

(Hardeep Singh) pinned #5

(hello kitty) #6

Its not a router vulnerability!!! its a client vulnerability, all routers will forever be vulnerable to this attack and no patch can be made for them because its not the routers that are being hacked at all but the client. the router is doing exactly what it was designed to do throughout the whole attack…

the only fix would be to impliment random nonces and avoiding reuse of old nonces, which involves completely rewriting the WPA_SUPPLICANT in all devices of all OS’s (some already do this ie macs) . this however will really mess up WPA2 and make wifi alot slower and glitchier since frames lost during very basic things every second wont be allowed to be used and have to be remade and recyphered… except 400% speed reduction if any client based WPA2 SU

(J Smith) #7

Has anyone seen an exploit in the wild yet?

(Hardeep Singh) #8

Well, I haven’t seen any yet. and as far as I remember Mathy denied to release any public exploit due to the potential damage it can cause to almost every part of the world.

(muwa00.dat) #9

this repo is the legit one, or maybe not ?

plus the demo :smile:

(Hardeep Singh) #10

Can someone verify if this actually works for showcasing Krack Attack. We’ll make a dedicated post for it if it is.


(Thomas) #11

I too am looking forward to seeing if this works. If it does, make a good video about using it and i will send the /r/HowtoHack community here.

(Hardeep Singh) #12

Sure thing.
I am a bit occupied right now.
Would test it in a day or two and post an update.

(Hardeep Singh) #13

@MrEcom Did you have a look at it?

(J Smith) #14

well well well… Let’s see what we have here. I’ll report back shortly.

(J Smith) #15

Alright, successfully installed the necessary tools and identified a vulnerable device. Tested several clients against the rogue AP including my cell phone and macbook. These devices were not vulnerable. However, my Samsung TV (I knew it would be) is vulnerable.

The above demonstration ( is based on the original tools done by Mathy Vanhoef. The tools by Mathy let you test clients to find a vulnerable one. Once you find a vuln device you can then create a rogue AP and have the client connect. The rogue AP fools the client into thinking it is the real AP and then you can sniff all traffic from the client. From what I’ve seen so far, this attack means you must be closer (or have a stronger signal) to the client than the real AP is, which limits the scope of the attack IMO.

Unfortunately, this is as far as I got. I ran into a little trouble as the Samsung TV (vuln client) connected to rogue AP, but did not get internet access. Therefore, I assume the rogue AP isn’t routing the TV’s data to the actual internet. So, once I fix that I’ll report back.

So far, this isn’t an attack on the router. It’s an attack on clients, but in my testing only a few clients are vulnerable. However, I think Samsung TVs (and other devices that do not regularly update firmware) are almost always going to be vulnerable.

Will report back when I know more.

(Hardeep Singh) #16

Right, TVs don’t usually get updates. My Sony Bravia although do receive updates, but I am not sure if it is still vulnerable of Krack. Will have to test.

I’ll see if I can invite the author of this git here and we can have a better view of the script, it’s working and maybe some new discovery.

Meanwhile we have to keep testing :slight_smile:

Maybe you’d have to enable IP forwarding for that?

(J Smith) #17

already on. Still doesn’t work. I think it has to do with the DNSmasq.conf file that the script generates automatically.

(Hardeep Singh) #18

Might be.

I’ll be testing it tomorrow and if everything worked fine, I’ll record a good video about using it as @T2112 suggested :grin: