vanhoefm
Joined 8 months ago
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7
Member since
Feb 26
Recent submissions
Comment · 8 months ago
It indeed seems we overall agree. Even if I may not have always explicitly said 'Wi-Fi encryption' for convenience, that can be derived from context normally, though it's always hard to estimate how people interpret text (and even harder to predict how others write about it :).
Comment · 8 months ago
When testing our own Enterprise devices, VLANs were not used. This was done to understand the impact of client isolation on its own.
For the university networks that we tested, I'd have to ask my co-author. But perhaps my other comment can further contextualize this: https://news.ycombinator.com/item?id=47172327 Summarized, I'm sure that it is possible to configure devices securely, and VLANs can play an important role in this. But doing so is more tedious and error-prone than one may initially assume, e.g., there is often no single setting to easily do so.
Comment · 8 months ago
That should definitely help. You still have to double-check the IP routing tables between the VLANs, but most of the time, that should prevent attacks between SSIDs.
Comment · 8 months ago
We don't have a CVE number. Whether devices/networks are affected also highly depends on the specific configuration of the device/network. This means that some might interpret some of the identified weaknesses as software flaws, but other weaknesses can also be seen as configuration issues. That's actually what makes some of our findings hard to 'fix': it's easy to say that someone else is responsible for properly ensuring client isolation :) Hence also hard to really assign CVE(s).
One of the main takeaway issues, in my view, is that it's just hard to correctly deploy client isolation in more complex networks. I think it can be done using modern hardware, but it's very tedious. We didn't test with VLAN separation, but using that can definitely help. Enterprise devices also require a high amount of expertise, meaning we might have missed some specialised settings.. So I'd recommend testing your Wi-Fi network, and then see which settings or routing configurations to change: https://github.com/vanhoefm/airsnitch
Comment · 8 months ago
People who use or rely on client isolation want to prevent inter-client attacks, for whatever reason. We show that this can often be broken. This can be problematic when you have older hardware in your network that is rarely updated, and many then rely on client isolation to mitigate attacks. If everything is encrypted and properly patched, then our attack indeed has less impact, but then there also wouldn't have been a good reason to use client isolation in the first place ;)
Comment · 8 months ago
I'm a co-author on the paper: I would personally not use the word break but instead bypass, to indeed clarify we can't just 'break' any network. We specifically target client isolation, which is nowadays often used, and that proved possible to bypass. If you don't rely on client/network isolation, you are safe.
Comment · 8 months ago
I'm a co-author on the paper: I would personally indeed not use the phrase "we can break Wi-Fi encryption", because that might be misinterpreated that we can break any Wi-Fi network.
What we can do is that, when an adversary is connected to a co-located open network, or is a malicious insider, they can attack other clients. More technically, that we can bypass client isolation. We encountered one interesting case where the open Wi-Fi network of a university enabled us to intercept all traffic of co-located networks, including the private Enterprise SSID.
In this sense, the work doesn't break encryption. We bypass encryption.
If you don't rely on client/network isolation, you are safe. More importantly, if you have a router broadcasting a single SSID that only you use, we can't break it.