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Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

krackattacks.com

281–290 of 424 posts

Re: Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

#281

As an Android user is there any mitigation for this other than ditching my handset and switching to an iPhone or waiting (hopelessly) for a patch from my vendor. This really does highlight the absolute disaster zone that the Android handset market has become as far as updates are concerned. I'm sure the Pixels will get a fix relatively quickly but almost every other Android user is going to be left in security limbo.

You should be good if you’re up to date as of November 6th (I think, it may be November 8th) Swiftonsecurity tweeted this out, it’s a description of KRACK and various devices affected by it. Apparently google already fixed it on android? Also it says that iOS is rumored to be protected against this since iOS 11 but it’s not confirmed. Nobody has put out an official statement yet. What’s weird is that commercial vendors like Ubiquiti UniFi (I use them myself) have already released fixes for their APs but the paper says that clients should be the priority and get fixed from KRACK ASAP. And it’s weird because I don’t know of any client-side fix released in the wake of KRACK being public. https://char.gd/blog/2017/wifi-has-been-broken-heres-the-com...

Re: Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

#283
post #167

Earlier quoted context omitted.

As others suggested ensure that all communication uses TLS (be it https et al or tunnel traffic through a VPN). Also you could install a better version of Android on your phone rather than an outdated vendor version. That will probably fix more security related issues than just this one :)

How would you make sure that apps use TLS for comunication? In the browser it's easy to see, but in apps those details are hidden away from the user.

Sniff the apps, uninstall if they don't, it's just plain unacceptable at this point. If there's something you really need that doesn't, set up a VPN.

Re: Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

#284
post #267

This is not an end-of-the-world type vulnerability. 1. Does not affect long-term credentials - certs, wifi passwords are still safe. Rather, confidentiality (secrecy) from client --> AP is affected, and in some cases packet forgery is possible (integrity). 2. Actually accomplishing this attack, for now, requires special and expensive hardware (med to high range SDR gear). Its also not that reliable outside of a lab e…

No, you do not need expensive hardware such as SDR to carry the KRACK attacks. Most plain standard WLAN adapters support AP mode, which is all you need to simulate the rogue network, as demonstrated in the video.

You still need proximity to the client, a powerful SDR will definitely improve reliability on real-life environments.

Re: Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

#285

Assuming neither client and router is upgraded, can this be mitigated my making the SSID hidden, so the attacker wouldn't know which AP to spoof?

hidden APs can be easily seen

Thanks, didn't know that :)

Re: Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

#286

As an Android user is there any mitigation for this other than ditching my handset and switching to an iPhone or waiting (hopelessly) for a patch from my vendor. This really does highlight the absolute disaster zone that the Android handset market has become as far as updates are concerned. I'm sure the Pixels will get a fix relatively quickly but almost every other Android user is going to be left in security limbo.

Ditch wifi, go 4G only!

There are many places indoors where I can get a WiFi signal but no cellular service.

Re: Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

#287

This is not an end-of-the-world type vulnerability. 1. Does not affect long-term credentials - certs, wifi passwords are still safe. Rather, confidentiality (secrecy) from client --> AP is affected, and in some cases packet forgery is possible (integrity). 2. Actually accomplishing this attack, for now, requires special and expensive hardware (med to high range SDR gear). Its also not that reliable outside of a lab e…

> 3. Everything you care about _should_ be going over TLS, which mitigates all effects of this attack.

This is probably the biggest misconception.

Many, many websites and APIs don't have HSTS enabled to force all connections to use TLS.

The author demonstrates using sslstrip to downgrade the connection of match.com to steal credentials.

How many people watch the green "secure" indicator in the URL bar to ensure it doesn't change mid-session?

How many thousands of apps don't even have such an indicator to observe?

How many millions of phones and APs will never get patched?

This is a severe vulnerability.

Re: Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

#288
post #218

> OpenBSD was notified of the vulnerability on 15 July 2017, before CERT/CC was involved in the coordination. Quite quickly, Theo de Raadt replied and critiqued the tentative disclosure deadline: “In the open source world, if a person writes a diff and has to sit on it for a month, that is very discouraging”. Note that I wrote and included a suggested diff for OpenBSD already, and that at the time the tentative discl…

This probably hasn't been exploited in the wild. Anyway the point of coordinating disclosure is to leave fewer people vulnerable overall. If one team releases a patch early, attackers can analyze the patch and start using the vulnerability against unpatched systems. Waiting for everyone to patch at once closes that window.

How can you state that it probably hasn't been exploited in the wild with any degree of confidence? It's possible that the same flaw was found and exploited years ago by black hat hackers and/or state security services. We have no way to know whether this actually happened, or even estimate the probability.

Re: Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

#289

As an Android user is there any mitigation for this other than ditching my handset and switching to an iPhone or waiting (hopelessly) for a patch from my vendor. This really does highlight the absolute disaster zone that the Android handset market has become as far as updates are concerned. I'm sure the Pixels will get a fix relatively quickly but almost every other Android user is going to be left in security limbo.

Ditch wifi, go 4G only!

Regarding mobile data in the US: https://news.ycombinator.com/item?id=15477286

Re: Key Reinstallation Attacks – Breaking WPA2 by Forcing Nonce Reuse

#290
post #36

Earlier quoted context omitted.

Note that in the demo video they use SSLStrip to cancel attempts of websites to switch to https. The only protection here is HSTS (which is not enabled by most websites, but major ones like banks will usually have them) and manually typing https:// in your address.

I'm seeing HSTS on 0/3 of Australian banks (I'm even seeing RC4 on one of them). https://www.ssllabs.com/ssltest/analyze.html?d=commbank.com.... https://www.ssllabs.com/ssltest/analyze.html?d=nab.com.au&s=... https://www.ssllabs.com/ssltest/analyze.html?d=westpac.com.a...

Commonwealth's online banking is actually at my.commbank.com.au and does have HSTS - https://www.ssllabs.com/ssltest/analyze.html?d=www.my.commba...

CUA does have it - https://www.ssllabs.com/ssltest/analyze.html?d=ob.cua.com.au

Bankwest does but has some awful problems elsewhere - https://www.ssllabs.com/ssltest/analyze.html?d=ibs.bankwest....

But yeah, Westpac and NAB don't, and in addition to the ones you tested, ANZ and St. George don't have it either. That's pretty unacceptable really.

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