Don’t Look Up: Sensitive internal links in the clear on GEO satellites [pdf]

20 hours ago (satcom.sysnet.ucsd.edu)

Some of the stuff that was extracted from the unencrypted traffic in the link:

- T-Mobile backhaul: Users' SMS, voice call contents and internet traffic content in plain text.

- AT&T Mexico cellular backhaul: Raw user internet traffic

- TelMex VOIP on satellite backhaul: Plaintext voice calls

- U.S. military: SIP traffic exposing ship names

- Mexico government and military: Unencrypted intra-government traffic

- Walmart Mexico: Unencrypted corporate emails, plaintext credentials to inventory management systems, inventory records transferred and updated using FTP

This is insane!

While it is important to work on futuristic threats such as Quantum cryptanalysis, backdoors in standardized cryptographic protocols, etc. - the unfortunate reality is that the vast majority of real-world attacks happen because basic protection is not enabled. Good reminder not take our eyes off the basics.

  • In https://satcom.sysnet.ucsd.edu/ Has The Issue Been Fixed section:

    >we re-scanned with their permission and were able to verify a remedy had been deployed: T-Mobile, WalMart, and KPU.

    The fact that critical infrastructure (e.g. utility companies using satellite links for remote-operated SCADA) was exposed is really scary too.

    • >The fact that critical infrastructure (e.g. utility companies using satellite links for remote-operated SCADA) was exposed is really scary too.

      Really serious security risks in critical/industrial infrastructure are ... numerous. And these aren't complex vulnerabilities, these are leaving the door open with default passwords, unencrypted traffic, and that sort of thing.

  • When driving by Bad Aibling I always wondered why the BND (intelligence agency) invests so heavily in satellite communication eavesdropping. I naively assumed that this kind of communication would be encrypted.

    Also a fun fact: For a long time it was only semi-officially known that the BND owned and operated the site. Officially it was called "Long distance telecommunications station of the Bundeswehr" and operated by the "Federal Office for Telecommunications Statistics"

    • At least since the mid-1990s Echelon revelations in the EU parliament anybody who cares knows that Bad Aibling (and similar stations all across Europe like Bude/Morwenstow in the UK) had been operated by the NSA in collaboration with US Army intelligence (if the official name of “18th United States Army Security Agency Field Station” didn’t clue you in.

      Officially it has been transferred to the BND; experience suggests all data from there still goes straight back to Fort Meade… (And in exchange the BND gets some morsels back on people _they_ are not allowed to spy on publicly.)

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  • I'm waiting for IT departments worldwide to wake up to the threat that your browsers are leaking all of your URI's by default back to the manufacturers.

    URI's leak company secrets. I'm sure there's some people at Google using Edge which are leaking company data to Microsoft. I'm sure there's some people at Microsoft using Chrome which are leaking data to Google.

    Edge and Chrome both send back every URI you visit to "improve search results" or to "sync history across devices". It's not clear if this includes private mode traffic or not (they don't say).

    Huge privacy hole to allow this, and nobody seems to be aware or care.

  • > This is insane!

    Not as insane as it was in the early 2000s…

    > while link-layer encryption has been standard practice in satellite TV for decades

    Before Snowden, I would say 99% of ALL TCP traffic I saw on satellites was in unadulterated plain-text. Web and email mostly.

    … the pipe was so fast, you could only pcap if you had a SCSI hard drive!

    • I was exposed to some of this as a teenager due to a (now dead) family member being heavily into telecoms. You could receive and process POCSAG (the protocol used by paging systems) to pretty much read the entire stream of unencrypted, plain text pager messages going out over the wire. You could also reprogram a generic pager to receive pages for whatever number you liked. You could also transmit your own POCSAG and send any number a page (only within your transmission range).

      SMS was also a bit like this in its early days and you could read them coming off the local cell (also true of calls at a certain time, but I didn't see much of this).

      I just did a quick search and apparently many pagers in the UK are still running cleartext POCSAG! https://www.reddit.com/r/RTLSDR/comments/1asnchu/are_uk_page...

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    • ```… the pipe was so fast, you could only pcap if you had a SCSI hard drive!```

      This is why NSA asked for (and got from SGI) a guranteed rate I/O API - to make sure that whstever the signal intelkigence platform sensors captured could be written to storage.

As with anything in life, when it's what you know and do on the regular, that simple thing can look like magic to others. I met an old timer in the satellite business that came out to help install our receiver for a new TV channel the company I was at was getting off the ground. He found out what bird we were using and what its slot was. Based on that, he knew how many satellites over from the satellite he knew and used as his base. It was a long time running TV channel that he could find very quickly. Once that bird was located, he just manually (literally pushed the dish with his hand) counting the number of satellites that came in/out of view until he landed on "our" bird. Once there, connected our receiver and baddaboom baddabing, there it was. Once the satellite was pointed at the proper angle to the south, it took less than five minutes from him connecting his receiver to verify his base signal to packing up and heading off the roof.

His base satellite signal was unencrypted and a main reason he used it for this purpose. Our channel was scrambled, and only verifiable after our receiver with the decoder was connected. It was impressive seeing someone that good at their job make it look so easy, but after he explained the layman's version of orbital slots it became less magical. This is why magicians are meant to not tell you how the trick is done.

  • Eh I kind of feel like you can't say that. If something is magical before you learn how it's done, it should be magical after. The magical part isn't "it's actually impossible", but "it's so far from what I could come up on my own", which still holds after you know the secret.

    • Yes, some excellent magic tricks work even better when you know how they work, especially if they’re the kind that’s based on putting in ridiculous amounts of work or skill/practice.

      Penn and Teller play a lot with that idea, for example.

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Ah, this brings back memories of listening to long-distance phone calls using a C-band dish and a general coverage (aka shortwave) receiver. Voice channels were placed on single-sideband channels between roughly DC and 6 MHz, and that whole set of signals was transmitted to the particular satellite transponder just like a video signal would be. The dish receiver couldn't decode that but it had a subcarrier output intended for accessories (stereo decoders maybe?). By plumbing the subcarrier output to the antenna input of the shortwave radio you could dial around to individual voice channels. I could only hear one side of the calls, but it was still very enlightening. I heard a number of mundane conversations, one drug deal, and a woman cursing in ways I'd never heard before. This was pre-internet and I was an impressionable kid - maybe 13 or so. Fun times.

Had a vendor offer a customer of mine a huge discount if they purchased radios without the encryption license in the year of our lord 2024.

Not even WPA or WEP. Just clear across the sky. And this is terrestrial.

My bet is that in space there would be a noticable increase in heat/energy if they did encryption by default. But its still incredible to see them pretend like space is impossible to get to, ultimate obscurity.

  • > My bet is that in space there would be a noticable increase in heat/energy if they did encryption by default.

    Why would it? The data originates from earth, and should be encrypted during the uplink leg too, so the crypto should all happen in the ground segment (or even well before it reached anything that could be considered part of the satellite setup, honestly).

    • Satellites have long lifespans and have to outlast current crypto algorithms. Ideally they're nothing more than radio repeaters that rebroadcast the uplink signal.

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    • Exactly, and the little bit of data actually destined for satellites – which includes momentum wheel and booster control – is something you’ll definitely want to at least authenticate.

      I believe that’s one of the few things that even amateur radio operators are allowed to encrypt for that reason.

    • The only thing I can think of is maybe the satellite company runs compression on the data. Encryption would prevent that.

  • Likely no consequences to the decision-makers for data exfiltration or other shenanigans happening, so there's nothing motivating a behavior change.

    The reason security is so bad everywhere is that nobody gets fired when there's a breach. It's just blamed on the hackers and everyone just goes on with life singing "We take security very seriously--this happened because of someone else!"

    • Who do you imagine will get fired? The CISO who's been recommending various security imporvements and been trying to get them implemented, but been unable to do so due to a lack of C level interest in IT. Or the C level's who lack interest in IT security until it bites them in the investor?

      At least here in the EU we're moving toward personal responsibility for C level's who don't take IT and OT security serious in critical sectors, but in my anecdotal experience that is the first time anything regarding security has actually made decision makers take it serious. A lot of it is still just bureaucracy though. We have a DORA and NIS2 compliant piece of OT that is technically completely insecure but is compliant because we've written a detailed plan on how to make it secure.

    • > nobody gets fired when there's a breach

      this must mean the consequences of such a breach has either not produced any visible damage, or the entity being damaged is uncaring (or have no power to care).

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  • Why does Space need to decrypt a vast majority of the traffic? Flow can be just as brick not-smart as fiber optic cables under the sea.

    Now, management, control, etc? Yeah those you need to decode in orbit.

  • The landing page has a Q&A. This is the relevant part of the response to the question, "Why aren't all GEO satellite links encrypted?"

    >Encryption imposes additional overhead to an already limited bandwidth, decryption hardware may exceed the power budget of remote, off-grid receivers, and satellite terminal vendors can charge additional license fees for enabling link-layer encryption. In addition, encryption makes it harder to troubleshoot network issues and can degrade the reliability of emergency services.

    So, the only suggestion that there would be greater heat/energy if they did encryption by default is the part about decryption (receiver) hardware having limited power budgets in some cases. There's more than what I copy-and-pasted above, but the overall message is that lots of organizations haven't wanted to pay the direct costs of enabling encryption... although they should.

    EDIT: Link to Q&A https://satcom.sysnet.ucsd.edu/#qanda

    • It's not a spacecraft issue. Encryption can be done at the ground stations, and mandated as part of the standards for interfsce equipment, just like with DOCSIS. There's nothing, physically, to stop you passing unencrypted traffic down your DOCSIS cable, if you wanted to make a nonstandard modem and send unencrypted traffic on your local physical segment of the network. But the rest of the network will refuse to talk to it.

      The same could have easily been mandated for satellite links - no encryption, your packet won't get forwarded to the internet at the ground station, and any packets sent to you from the internet will be sent to you encrypted. And all this can be implementd without needing to touch the satellite itself, which will continue to forward what it sees as unencrypted traffic without any design changes. It could even have been implemented incrementally on existing running services, with old and new equipment working side-by-side, but all new ground stations required to support encryption, and with a sunset date for old equipment, and a rolling upgrade program.

      DOCSIS got this right in 1999; the satellite industry has had 25 yeqrs to catch up.

  • Encryption is basically free as far as I know, but it is more complex and it must be hard to get software updates up there.

    • Here is their excuse:

      > Panasonic told us that enabling encryption could incur a 20–30% capacity loss. In addition, when using IPsec, ESP and IP headers can introduce 20–30 bytes of overhead, which is nontrivial for small-packet applications like VoIP and video calls

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  • I mean a bunch of those crypto systems turn out to be flawed though. So skipping the vendor implementation and using something in software instead could make sense.

I was working in space industry and ECSS security guidelines are missleading grant seeking startups to try to reinvent TLS on orbit. There are to mamy bureaucracy. ECSS guidelines for software teams were created by people who never written a Hello World in their life, just look at specs of ECSS Packet Utilisation Service, it's a joke, that's why I prefer to work for VC funded companies than grant funded.

Section 6.3.2 is an eye-opener... good lord... Gets even worse at 6.4.2-3

  • Am I offtrack in wondering if by reverse engineering the mentioned in-the-clear ATM communications you could (in theory) inject some malicious packets and in effect just dispense cash to yourself with a laptop and a dish? How very cyberpunk.

  • It's absolutely jaw-dropping. Either no-one at these companies was capable of understanding the problem, or no-one cared enough to do something about it.

    • From my time in similar companies, some people understand, and might care, but aren't empowered to do anything about it. They've got a job to do, and creatively auditing network security isn't it. Finding this kind of issue on the company clock won't get them promoted, on the contrary they'll look like they're slowing the team down with vulnerabilities to fix when they've got stuff to build and sell. Very poor security culture.

Absolutely mind-boggling that this is a thing; not just that satellite links aren't per-user link-encrypted, but also that people are still using unencrypted protocols to exchange sensitive information on the public internet in 2025.

Is it correct to Assuming the amount of Mexican companies in this paper is because of their receiver being in the major city southwestmost corner of the country ?

  • Yeah that's correct. The study was conducted in San Diego which falls under the satellite beam footprint required for services in Mexico.

    If you were in say, Alice Springs in Australia (wink wink) for example, you'd be able to see traffic for Indonesia, Philippines, most of South East Asia, and perhaps parts of China, South Korea and Japan if the beams are right.

Does anyone remember the days when you pointed a 60cm antenna at the Hispasat 30W and connected your DVB-S2 tuner in Windows, Using Crazycat's BDADataEx, you tuned an IP data transponder. Using a technique called Satfish (with a software I don't remember), some files were reconstructed, usually vsat data from oil platforms... and porn.

I'm going to dust off the TBS DVB-S2X card and try to find a data transponder to test the DontLookup app. https://github.com/ucsdsysnet/dontlookup

Where I live, it's almost impossible to find any interest in FTA or pirated SAT TV.

att: ham radio operator interested in satellite radio :D

  • My understanding has been that the majority of FTA TV in the western hemisphere is religious in nature, and that's simply not a tempting onboarding bait for a lot of people to buy the gear and start exploring. The vast majority of satellite TV receivers in the US are propretary VSAT services, not equipped for exploring wild feeds and things.

    My understanding is that elsewhere, there's a lot more interesting stuff FTA so a lot more people have the hardware, and the hardware itself is more generic. So there's just more opportunity for someone to get bored and discover a new hobby a few degrees to the side of their usual watering hole.

Who needs hackers when companies broadcast their secrets to half the planet?

  • Intercepting non-obvious (in the sense that you can't just, like, open your wifi menu and see them) broadcasts is still hacking. Heck, even intercepting obvious (in the sense that it says "your data is not secure" on the screen of the people communicating) broadcasts is still hacking. Doing what Firesheep does, before Firesheep, was hacking. And then someone made Firesheep and it was still hacking, but now anyone could do it by clicking a few buttons, without any hacking skill whatsoever, not even using a command line, so it was finally patched.

In view of this disclosure I am even more dissapointet T-mobile satellite service (via starlink) does not support Signal messenger.

As an aside, the PDF metadata says it's generated from LaTeX, but the layout and typesetting looks better than the LaTeX output I'm familiar with. Nicely done.

  • The body font appears to be Libertinus Serif (and I assume Libertinus Sans is the seldom-used sans font), which I agree look much nicer than the default Computer Modern

I see no issue with the satellite backhaul itself being unencrypted; anyone using the satellite provider should assume they're hostile and encrypt+authenticate everything they send anyway. I don't trust my ISP's fiber to be snoop-resistant just because they nominally have some shitty ONT encryption.

Obviously the specific examples of end-users failing to encrypt are bad, but that's not really a problem with the satellites.

  • If someone is browsing the internet on in-flight wifi, and their DNS requests get leaked this way, I don't really think its the casual airline user's fault for not encrypting their DNS traffic. Modern cell phone data traffic (4G/5G) is all encrypted, so the same unencrypted DNS requests can't just be passively sniffed. Something similar should happen here.

    I'd blame the airline or their ISP provider for sending unencrypted traffic through the air like this. Not the satellite, but its top level customer. There's a big difference, IMHO, between your ISP being able to sniff your fiber traffic, and your traffic being observable from ~30% of the globe.

  • This. Bytes on every medium can be snooped. Internetworking means that your bytes go on mediums you don't know about and don't control. There's no such thing as a link where encryption is not needed, except localhost.

Tangential, but I was very surprised to learn recently that my country still has a more or less nationwide POCSAG pager network where only some users encrypt their traffic

From the Introduction: "Each satellite may carry traffic for dozens of independent networks through an array of on-board transponders, each covering a diameter of thousands of kilometers (at most a third of Earth’s surface)".

Can someone help me understand the use of "diameter" in this sentence. I am guessing it refers to the satellite's signal coverage of the Earth's surface. If that's the case, wouldn't something like arc degrees be a better measure? I just can't figure out how "diameter" can be used to describe a coverage arc or area.

  • They mean the intersection between the cone produced by the satellite and "illuminated" surface. If the antenna beam is normal to the sphere, it will produce a disk which has an diameter.

I wonder why the DOI link on the bottom left of the first page does not work:

https://doi.org/10.1145/3719027.3765198

  • It’s quite common for a DOI to be assigned to a paper after it’s accepted during camera ready. However, the DOI won’t work until the conference or journal version is published on the official website (ACM in this case). The version you’re viewing now is simply a preprint directly from the authors.

    • Exactly! It says this as one of the 3 reasons for DOIs not found on the error page:

      >The DOI has not been activated yet.

> remarkably, nearly all the end-user consumer Internet browsing and app traffic we observed used TLS or QUIC

There was a surprising amount of resistance to the push to enable TLS everywhere on the public Internet. I'm glad it was ultimately successful.

  • It was only successful because Google said you'd rank higher if you did it.

    • It was only successful because of Let's Encrypt removing any excuse for not having HTTPS on your website, HSTS becoming a thing, and Chrome moving from gentle inducements (that cute green padlock) to nasty looking warnings if you didn't use encryption.

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  • > I'm glad it was ultimately successful.

    What are you talking about? It was an absolute failure.

    As soon as we got widespread TLS adoption, Cloudflare magically came along and wooed all the nerds into handing over all the plaintext traffic to a single company.

  • It has improved security, but it has made it less durable. Hosts now need constant maintenance to keep up with changes to TLS policies, certificate renewal protocols and so on.

I think that the risk of anybody achiving a malicious outcome by accessingn these data streams is as spectacularly low as the effort required to get the signal and then figure out some context to the randomised transmissions and then weaponise that is high, very high. Presumably it is GB/sec by however many channels, 99% of it will dry your eyeballs out and quickly render even the most determined spook a quaking quivering mess huddled in the corner of an office screaming " make it stop" the researchers behind this are just showing off, but I will bet any money, nothing but nothing could keep them there going through the worlds slop, which a smart, counter spook would insure was a regular and tantilising portion of the signal to begin with. the issue is that these sattelites are just repeaters, and there is little ryme or reason to the content, and personel good enough to work it, can find much much more profitable things to do.

  • A lot of low population density cellular backhaul runs over satellite. Two factor SMS or voice can be directly intercepted, assuming encryption is not used.