26 ms·
Key Negotiation of Bluetooth Attack
- geerlingguy 7y agoWhat isn't clear is if you have a device like a laptop, phone, or tablet, and it _is_ updated post-late-2018... will that protect you from the vulnerability even if you're using an older Bluetooth device (e.g. keyboard, headset, etc.) that isn't going to ever get an update? [Edit] Found some relevant information from the Bluetooth.com security notice[1] > For an attack to be successful, an attacking device would need to be within wireless range of two vulnerable Bluetooth devices that were establishing a BR/EDR connection. If one of the devices did not have the vulnerability, then the attack would not be successful. [1] https://www.bluetooth.com/security/statement-key-negotiation-of-bluetooth/ https://www.bluetooth.com/security/statement-key-negotiation...
- sp332 7y agoAccording to https://www.kb.cert.org/vuls/id/918987/ https://www.kb.cert.org/vuls/id/918987/ either side can propose a new amount of entropy and the other side can accept or reject it. An updated controller firmware on either side could reject the connection. Another option mentioned in the paper is for the OS to check the entropy level and close the connection after each renegotiation. I'm not sure if OSes have actually been updated to do that, but it would work for all kinds of devices even without hardware vendor support.
- grenoire 7y agoA rejected connection means a bricked device, on the other hand. Sure, newer drivers could protect me against attacks, but simultaneously prevent me from using my BT headphones.
- sp332 7y agoHopefully this would only be an issue during an attack. Not sure why your headphones would be legitimately negotiating encryption but then only supporting <7 bytes of entropy.
- jkhfg98pghbjkl 7y agoThat's not difficult then, order one of these https://www.raspberrypi.org/products/raspberry-pi-zero-w/ https://www.raspberrypi.org/products/raspberry-pi-zero-w/ , get a battery pack and fix to some unsuspecting CEO or other juicy corporate targets vehicle. Saves trailing the vehicles and thus raising suspicion. How many car manufacturers do you think update their vehicles Bluetooth stack? Mr Robot.
- ggg3 7y ago> phone > updated phones only get a couple updates so you keep buying them new.
- ayakura 7y agoDirect link to research paper: https://www.usenix.org/system/files/sec19-antonioli.pdf https://www.usenix.org/system/files/sec19-antonioli.pdf Relevant results are on page 1057. It's crazy to think all of the devices tested were vulnerable up to Bluetooth 5.0, but at least the attacker would need to be within range of broadcast, as another user pointed out
- ryanisnan 7y agobut at least the attacker would need to be within range of broadcast So anyone who lives in a small footprint high-rise or spends ample time on a coffee shop. Yikes! edit: format
- hdasika 7y agoprobably need to check the update release notes if there is any mention about fixing this on the devices.
- lost_name 7y agoKind of a tangent, but I was traveling in Portugal last year, and one day as I was headed to a train station I felt my phone buzz. I picked it up and it had a failed Bluetooth file transfer. In the settings, the device name had changed from the default to what looked like a base64 string, if I remember correctly. Unfortunately I didn't think to screenshot anything. The phone was literally only a couple weeks old. Nothing new had been paired. I changed the name back and figured I would look it up later. The failed file transfer was automatically cleared (just a phone thing) and I wasn't able to find information about it.
- robbyt 7y agoA similar thing happened to my phone while I was at Defcon several years ago. After that I put my phone on airplane mode. Then when I got home, I reset all my passwords, and wiped the phone.
- tuvan 7y agoIs people trying to hack the attendees a common occurrence at Defcon?
- zaeirrka 7y agoNo its more of an urban legend. I'm sure there's some hijinks going on but I doubt the hotels would tolerate any kind of large scale malicious activity especially with all the unrelated people staying at the hotel
- filleokus 7y agoHaven't worked my way all through the paper yet. But is it correct that an attacker can perform this attack to something like a keyboard that has been previously paired and everything? What kind of user "interaction" would be required? Will the OS re-pair the device and (possibly) notify the user? This seems really powerful and dangerous. Probably not that many people who uses laptops and BT keyboards, but many of the iPad keyboard covers uses bluetooth.
- spzb 7y agoNot a Bluetooth expert and I might have misunderstood the paper but it seemed like it can be done any time two devices initiate a new connection (not when they're paired but anytime they start communicating). AFAIU, it's a firmware level hack so not something you can do with standard Bluetooth functionality. You need to be able to get a custom firmware into the Bluetooth chipset to carry off an attack.
- capitol_ 7y agoI presume that you could pull it of with a SDR.
- stri8ed 7y agoGood question. Can the attacker force an existing paired device to re-negotiate the pairing process, or is this attack only viable against devices that have not yet paired?
- clort 7y agoI think an attacker can disrupt already existing connections causing them to reconnect but if they try to re-pair then operator interaction would be required. I think that this attack only works when the encryption is being negotiated, which is usually when the connection is made (you can do it later, or redo it at any time)
- peter_retief 7y agoAre there any known similar vulnerabilities for OpenThread? I suspect Thread would be more secure and probably a better choice for meshed networks
- gruez 7y agoHow easy is this attack to pull off? Doesn't bluetooth use spread spectrum? If so, you'd need to somehow predict the frequencies that will be used, which is non-trivial because it's generated from the link key.
- AWildC182 7y agoAt least for listening, a $100 software defined radio would be able to sample the whole band in one go without needing to follow the frequency hops.
- mokus 7y agoI don’t think the price point is quite that low yet, is it? I have a couple I bought for $250 that can do that, but I’m not aware of a readily available radio that can receive 80MHz+ at that price point. If you can point me to it, I’ll probably buy a couple immediately.
- jsjohnst 7y agoI own most of the commonly available SDRs, and I’m also not aware of any that can do that wide of a range at $100 price point. Like you, I’d be happy to be proven wrong (albeit my wallet won’t be).
- rasz 7y ago79MHz, so you will need 4x $100 HackRF (price for bare board, no case/cabling). https://www.ebay.com/itm/HackRF-One-1MHz-to-6GHz-Software-Defined-Radio-Platform-Development-Board-T9Q0/362708960943 https://www.ebay.com/itm/HackRF-One-1MHz-to-6GHz-Software-De...
- jsjohnst 7y agoI have several HackRF boards. That’s not 80MHz for $100, that’s 20MHz for $100.
- 7y ago
- chromaton 7y agoRecently there was an update to my Android on my Samsung Galaxy S8 that makes it HARDER to see if Bluetooth is turned on. I like to leave it off whenever I'm not using it to try to reduce the attack surface.
- Fogest 7y agoNot sure this is really the same thing. However in my case I like it harder because I use bluetooth multiple times a day with my phone and it's annoying having a persistent icon showing me it's on despite not caring.
- miohtama 7y agoObvious attack target: Bluetooth keyboards for keylogging.
- koolba 7y agoObvious solution: never use wireless input devices. Has the added benefit of never having to deal with charging batteries or charging.
- dangus 7y agoWell you can avoid all software vulnerabilities by not using computers at all, right? Maybe I should use an Ethernet cable on my iPhone instead of LTE, that should be convenient.
- throwamay1241 7y agoAs soon as people stop treating the physical layer as a security control, the better. Encrypt your damn comms.
- xnyan 7y agoObvious solution, don't use anything that emits electromagnetic radiation: https://en.m.wikipedia.org/wiki/Van_Eck_phreaking https://en.m.wikipedia.org/wiki/Van_Eck_phreaking
- wincy 7y agoWell, time to go back to typing everything on a typewriter.
- vardump 7y agoYour data will leak regardless because of typewriter keystroke acoustics [0]. So you better have a soundproof room for that purpose. Keep any electronics out of the room that might have a microphone. Like phones, laptops, or running mechanical hard drives [1]. [0]: https://arxiv.org/abs/1609.09359 https://arxiv.org/abs/1609.09359 [1]: https://spqr.eecs.umich.edu/papers/Kwong-HDDphone-IEEE-SP-2019.pdf https://spqr.eecs.umich.edu/papers/Kwong-HDDphone-IEEE-SP-20...
- hannob 7y agoWhat is even more bananas than the mere existence of this attack is the statement of the bluetooth standardization group: https://www.bluetooth.com/security/statement-key-negotiation-of-bluetooth/ https://www.bluetooth.com/security/statement-key-negotiation... Here's their plan to fix this: "To remedy the vulnerability, the Bluetooth SIG has updated the Bluetooth Core Specification to recommend a minimum encryption key length of 7 octets for BR/EDR connections" 7 octets, aka... 56 bit. So it looks like this vulnerability is here to stay. They just raise the bar from "trivially breakable" to "you need a bit of cloudcomputing effort to break a connection".
- jwtorres 7y ago7 octets is the minimum set by the SIG, not a mandatory length to support for all devices. For devices that transfer sensitive information (phones, keyboards, etc.), a larger key length can be enforced. This would be enforced by the application written by the product designer, not the BT chipset vendor nor the BT SIG.
- jjoonathan 7y agoWhy 7? Is that the longest key the NSA can crack quick enough to mount the attack?
- LeonM 7y agoI expect it's a trade-off between power usage and brute-force resilience.
- stuaxo 7y agoThis naming is very unfortunate, but hilarious to any Brits.
- davestephens 7y agoVery amusing, but definitely missing a trick on the Blue/KNOB combo.
- azinman2 7y agoI think it’s on purpose. One of the authors is from Oxford after all...
- weinzierl 7y agoSorry for my ignorance. Can you explain the reference?
- vonholstein 7y agoI presume that the parent is referring to https://www.urbandictionary.com/define.php?term=Knob https://www.urbandictionary.com/define.php?term=Knob. Warning NSFW text.
- rkachowski 7y agoCalling someone a "knob" is a bit softer than calling someone a "dick", but they both refer to the same body part.
- throwaway_391 7y agoFrom the article 'Key Negotiation of Bluetooth'. Basically, researchers started naming vulnerabilities when they thought they mattered. 'Shellshock' and 'EternalBlue' are both deserving of names, IMO. Then researchers started naming everything, many of the vulnerabilities had zero real world impact, were almost entirely theoretical (many crypto vulns), or required chaining of other attacks to actually achieve anything. The KNoB description says 'is vulnerable to packet injection by an unauthenticated, adjacent attacker that could result in information disclosure and/or escalation of privileges.' which is sounds extremely caveated. They haven't demonstrated an actual attack so my guess is they've overplayed the significance of the vulnerability entirely and this grants the ability to PITM traffic (which really isn't a defensible boundary, anyway). Most decent hackers I know laugh at named vulnerabilities unless their technical impact actually matters. Dirty COW took the piss entirely, https://dirtycow.ninja https://dirtycow.ninja, https://www.zazzle.com/collections/white_theme-119587962650451153 https://www.zazzle.com/collections/white_theme-1195879626504... .
- mintplant 7y agoIn case anyone else is wondering: I believe this doesn't affect Bluetooth LE Secure connections, though the authors don't state that explicitly.
- SwaraLink 7y agoThat is correct. The vulnerability note clearly states that this only impacts "Bluetooth BR/EDR Core v5.1 and earlier". "BR/EDR" is the technical term for Classic Bluetooth; in other words not Bluetooth Low Energy.
- mintplant 7y agoThe authors state that it impacts BR/EDR, but not exclusively so. If the standards shared enough aspects of their key negotiation protocols, then both could potentially be impacted. After scanning through the paper and the relevant details of the LE Secure pairing process, that does not appear to be the case, fortunately.
- deleted 7y ago[deleted]
- driverdan 7y agoWas this known previously or was there another entropy attack? I remember reading about this or a similar attack a while ago but don't remember if the details matched.
- wtdata 7y agoDoes this mean we will finally be able to easily and quickly, hack that pesky people forcing us all to listen to their Bluetooth speakers (invariably with bad music) on public transports?
- ktpsns 7y agoThat sounds as a funny side project. Hijacking Bluetooth speakers.
- ktpsns 7y agoThat especially means: don't use a Bluetooth keyboard. Never.