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The weak-point is the shared USB device that copies from one machine to another which seems to defeat the whole purpose of being air-gapped - you could have pri
by benoau 2y ago
The weak-point is the shared USB device that copies from one machine to another which seems to defeat the whole purpose of being air-gapped - you could have printed-and-OCR'd data three decades ago so the air-gapped machine is never reading anything from outside at all, these days a video stream and AI could probably automate that?
- kibwen 2y agoSurely some government has come up with physically-unidirectional data transmission mechanisms for getting data onto airgapped networks. There has to be something more sophisticated than single-use CD-ROMs, even if it's just a blinking LED on one end and a photosensor on the other end.
- neonz80 2y agohttps://en.wikipedia.org/wiki/Unidirectional_network https://en.wikipedia.org/wiki/Unidirectional_network
- maxerickson 2y agoWhich ironically describes them evolving into software driven gateways.
- wannacboatmovie 2y ago> There has to be something more sophisticated than single-use CD-ROMs But why, when a DVD-R handles most use cases at a cost of < $0.25 each, are reliable and ubiquitous, the hardware is likely already there (unless you are using Apple - caveat emptor) and they close the threat vector posed by read/write USB devices. Sometimes the simplest solution is the best solution.
- rhcom2 2y agoI would guess having a CD/DVD drive opens another attack surface. Similar to why people gluing their USB ports closed.
- zmgsabst 2y agoRight — but the question isn’t CD/DVD versus nothing. It’s CD/DVD versus USB; and which has a smaller attack surface. I’d argue that read-only CD/DVD has a smaller attack surface than USB, so of the two, it’s preferable. I’d further argue that a CD/DVD (ie, the actual object moved between systems) is easier to inspect than USB devices, to validate the behavior.
- RF_Savage 2y agoThe CD/DVD discs used can also be retained and later audited to verify what was moved to and from the systems.
- sneak 2y agoDVD-R is read/write unless you are very careful to have read-only hardware on the destination device.
- roywiggins 2y agoYou can always shred the DVD afterwards I guess!
- alwa 2y agoEven if the destination device were to write something to said discs, the optical media are cheap enough that it makes sense to destroy them (or archive them in case they become useful for forensic purposes) rather than reusing them. Plus, compared to a USB form factor, one imagines it’s harder to sneak in circuitry that could retransmit data by unexpected means.
- BlueTemplar 2y agoWhy "very" ? Also, if you think that the seller is lying to you, can't the drive be opened up and inspected to check for that kind of capability ?
- ahartmetz 2y agoI have heard (on HN) of... 100 MBit ethernet with the transmit wires cut. Probably in the context of in-flight infotainment: plane data to infotainment yes, infotainment anything to plane control anything no. If it's stupid but it works...
- nullc 2y agogigabit fiber works fine, amazon sells splitters, split tx and loop back to rx on the tx side. Rx side just works. you need to use a file transfer tool intended for unidirectional transfer (e.g. multicast) otherwise you will have failure from lost packets. If you don't require high speed just use RS232.
- guenthert 2y agoIt was used to connect network monitors (packet capturing devices) to ensure that ARP or a bug or misconfiguration wouldn't reveal the existence of that device on the network.
- SAI_Peregrinus 2y agoGood old UART without the RX connected on one side.
- aenis 2y agoAlas, this can be reconfigured without anyone noticing, assuming compromise on both sides. A diode / photosensor can't.
- nl 2y agoData diodes are commonly used: https://csrc.nist.gov/glossary/term/data_diode https://csrc.nist.gov/glossary/term/data_diode I don't know if people class something connected using a data diode as airgapped or not.
- fuzzfactor 2y agoRegular two-way IR diodes and sensors were standard on 90's business laptops for ordinary RS-232 file transfer between machines wirelessly. Before wifi or even ethernet was everywhere, and before USB and Bluetooth came along. The first smartphones had it too so you could dial up the internet on the road in the years before phones had a browser and stuff like that.
- matco11 2y agoYes. …and, indeed, that used to be a vector for hacking “air gapped” systems back in the day
- firesteelrain 2y agoAirgapped from the Internet —- yes.
- coopreme 2y agohttps://docs.aws.amazon.com/whitepapers/latest/cross-domain-solutions/connecting-cloud-to-cloud-infrastructure.html https://docs.aws.amazon.com/whitepapers/latest/cross-domain-...
- khaki54 2y agoYeah they exist. Data diodes or data guards. They operate at currently available line speeds and there are 100s of thousands in operation. Data diodes are favored by OT companies. For government, Data Guards as they tend to have more robust inspection
- mitjam 2y agoSD cards can also have a switch to make them read only.
- gnabgib 2y agoThey have a switch that requests the host doesn't try and write, but it's not read only: It is the responsibility of the host to protect the card. The position [i.e., setting] of the write protect switch is unknown to the internal circuitry of the card https://en.wikipedia.org/wiki/SD_card#Write-protect_notch https://en.wikipedia.org/wiki/SD_card#Write-protect_notch
- dwattttt 2y agoAh, security via the honour system. Unbeatable
- deleted 2y ago[deleted]
- zahlman 2y agoI can definitely imagine use cases where a network is air gapped internally for security but bidirectional transfer still takes place. The point is that humans are supposed to be in control of exactly what is transferred, in both directions (not feasible with a network connection, to my knowledge).
- benterix 2y agoYes, humans are in control, but in the case of Windows the humans that control the default behavior of the system when an USB device is connected are not the ones that are using it. Frankly, I wonder why implement an air gap if Windows is being used. Even in the case of Linux a hardened configuration should be used.
- jonathanstrange 2y agoWindows can be hardened as much as Linux and has less attack surface for supply chain attacks. At least, the latter holds when you believe Microsoft as company is overall more secure and less compromised than tens of thousands of open source contributors working from home.
- benterix 2y agoI'm not discussing the general situation as the topic is too vast, just this particular case of OS reaction when a device is connected.
- dotancohen 2y agoIn both Windows and Linux the amount of people contributing code are roughly within an order of magnitude equal. The difference is that with Linux we understand that every commit must be verified. We do not know to what extent Windows upholds that same standard.
- fsflover 2y agoWhy the false dichotomy? One should use an OS dedicated to security, e.g., Qubes OS.
- theamk 2y agoThe things are much easier: two parts, one has blinking LED, another is photosensor. This is called "data diode" and there is a lot of them. Here is a random vendor with nice pictures: https://owlcyberdefense.com/learn-about-data-diodes/ https://owlcyberdefense.com/learn-about-data-diodes/
- eastbound 2y agoAn optic fiber.
- dangsux 2y ago[dead]
- jalk 2y agoSo one-way IrDa?
- folmar 2y agoYes, but the vendor also gives some reasonable transmission software that will be able to transmit common protocols (like OPC/DB updates and so on) multiplexed and abstracting away the confirmationless medium.
- ibeff 2y agoLet's hope the photosensor processing software on the receiving end doesn't have any bugs that could be exploited.
- TacticalCoder 2y ago> The weak-point is the shared USB device that copies from one machine to another which seems to defeat the whole purpose of being air-gapped... Yup. I was going to post that TFA and the people at these embassies apparently have a very different definition of what people consider an air-gapped system. Pushing the non-sense a bit further you could imagine they'd recreate ethernet, but air-gapped, using some hardware only allowing one packet in at a time, but both ways: "Look ma, at this point in time it's not talking to that other machine, so it's air-gapped. Now it got one packet, but it's only a packet in, so it's air-gapped! Now it's sending only a packet out, so it's air-gapped!". Yeah. But no.
- PhilippGille 2y ago> TFA and the people at these embassies apparently have a very different definition of what people consider an air-gapped system. And Wikipedia? Which says: > To move data between the outside world and the air-gapped system, it is necessary to write data to a physical medium such as a thumbdrive, and physically move it between computers. Source: https://en.m.wikipedia.org/wiki/Air_gap_(networking)#Use_in_classified_settings https://en.m.wikipedia.org/wiki/Air_gap_(networking)#Use_in_...
- eviks 2y agoHow would you get data or even the OS itself to the machine under your definition?
- csomar 2y agoI created such a system (though to transfer Bitcoin Transactions/Signatures from an airgapped system). The problem is that if you have a lot of bi-directional traffic, you'd want to automate the process of scanning/storing the information. Suddenly, you just have a slow USB device. What you want is to minimize your data to less than a 1Kb so that it can be manually transmitted.
- jack_pp 2y agoWouldn't it be easier to just have every port blocked except for a very simple application which has no privileges and just writes ASCII to some file? Such an application would be very easy to audit
- cryptonym 2y agoUntil someone finds a bug in the network stack
- Aachen 2y agoI think the general point stands though. While nothing is perfectly secure, having small and understandable components that are fully audited should allow a high level of safety If a network stack on a modern computer is too dangerous, then use a modem (silly example: apt install minimodem) and an aux cable from the one computer's speaker to the other's mic jack, or a serial connection (not very familiar with those, can't say how complex the driver is there) or something similarly basic that you can audit a memory-safe implementation of
- cryptonym 2y agoYou advocate for really simple application layer, while having that on top of all the other complex communication layers. Implementations had multiple known vulnerabilities over the years. In case of vulnerability an attacker might be able to do much more damages with real-time access. Is it any safer than an USB stick?
- seeknotfind 2y agoLol. Even if it's with the QR code, it will not be safe. If you can read a bit, you can read a file. Security is a mote, and the hacker is a catapult. Any sufficiently complex system, any metric of security will be incomplete or ignoring that Turning complete and uncomputable. Security is about intelligence in all layers of the stack, from the electron to the application and even the front door. A USB exploit attacks a driver or the OS. A QR code attacks the application. There are other ways to exploit besides breaking and entering. Sometimes it's about influence. In the age of AI, the entire internet and all knowledge could be shifted to reframe a single organization to make an exploit possible. Pandora's box is wide open. It's pouring out. Even a machine on the internet can be secure, but an air gap is only the transport layer. It's a false sense of security. You need to be worried about the full stack because that's the only way to be safe, to never be safe, the eternal guard and gaze. The vigilance. Security in layers. Security in depth.
- iforgotpassword 2y agoArguably the qr-code based approach would be much safer, as it would be much simpler to implement and audit. Moving a USB key between two windows machines sounds as bad of an idea as it can get for airgapped data exchange.
- ben_w 2y agoOnly if it's done right; when I first made this image, the scanners built into phones straight up executed the JavaScript: https://benwheatley.github.io/blog/2017/04/2017-04-10-11-15-23.jpg https://benwheatley.github.io/blog/2017/04/2017-04-10-11-15-...
- mistercheph 2y agoSure, but if you have resources to spend validating the security of a tool, would you rather validate the QR parser or the USB stack?
- XorNot 2y agoThere are forensic USB write blockers which sit between the USB device and prevent host-writeback to the device.
- notorandit 2y agoExactly. Air-gapped means non data going in and out of systems. USB stick are acting as a cable.
- rkagerer 2y agoYou're on the right track in the sense that a key characteristic for a successful air gap is diligent human review of all the information that flows in and out.