Source Link Privacy.
Tarlogic Security has detected a backdoor in the ESP32, a microcontroller that enables WiFi and Bluetooth connection and is present in millions of mass-market IoT devices. Exploitation of this backdoor would allow hostile actors to conduct impersonation attacks and permanently infect sensitive devices such as mobile phones, computers, smart locks or medical equipment by bypassing code audit controls.
Update: The ESP32 “backdoor” that wasn’t.
We really should be pushing for fully open source stack (firmware, os) in all iot devices. They are not very complicated so this should be entirely possible. Probably will need a EU law though.
Open source stack will not prevent this. It’s not even a backdoor, it’s functionality that these researches think should be hidden from programmers for whatever reason.
Open source devices would have this functionality readily available for programmers. Look at rtl-sdr, using the words of these researches, it has a “backdoor” where a TV dongle may be used to listen to garage key fobs gasp everyone panic now!
thats a very fair point, I had not seen anyone else make this one But the problem is that in this case, this functionality was entirely undocumented. I dont think it was intended for programmers.
Now if the firmware was open source, people would have gotten to know about this much sooner even if not documented. Also such functionality should ideally be gated somehow through some auth mechanism.
Also just like how the linux kernel allows decades old devices to be at the very least patched for security risks, open firmware would allow users of this chip to patch it themselves for bugs, security issues.
Yeah, of course, it would be better in many ways if the firmware wasn’t closed.
Yeah tons of weird little private softwares never get updates, but they aren’t making anyone money either
Backdoored devices are useful for people who can impede that.
And the way EU is approaching privacy, surveillance and all such, - oh-hoh-ho, I don’t think there will be a EU law.
This sounds like there are some undocumented opcodes on the HCI side – the Host Computer Interface – not the wireless side. By itself, it’s not that big a deal. If someone can prove that there’s some sort of custom BLE packet that gives access to those HCI opcodes wirelessly, I’d be REALLY concerned.
But if it’s just on the host side, you can only get to it if you’ve cracked the box and have access to the wiring. If someone has that kind of access, they’re likely to be able to flash their own firmware and take over the whole device anyway.
Not sure this disclosure increases the risk any. I wouldn’t start panicking.
So explained to me, a tech illiterate in comparison, this is China bad scaremongering?
‘Backdoor’ sounds malicious with intent.The article is a security company trying to hype their company with a theoretical attack that currently has no hypothetical way to be abused
The article has an update now fixing the wording to “hidden feature” but, spoilers, every BT device has vendor specific commands.
The documentation of the part just wasn’t complete and this companies “fuzzing” tool found some vendor commands that weren’t in the data sheet
The China part just came from OP
The article is a security company
trying to hype their companyruining their reputation in an incredibly ill-thought out attack that companies will ABSOLUTELY remember.Even worse, it just makes this security company look incompetent. Like a home security company that announces a huge vulnerability in Schlage locks- there’s a key that can unlock the lock included with every lock sold!!11!!!11!one!
I agree, but unfortunately, this has become common since Heartbleed, and they seem to be able to sell their snake oil to CTOs…
thank you
Pull up a chair and pour yourself a stiff beverage…
TLDR: Don’t Panic.
If you have a regular old processor (MCU) and want to give it wireless capability, you can buy a wireless chip and stick it next to the processor, then have the MCU talk to it through a wired connection (typically UART or SPI). Think of it as the old ATDT commands that had your PC control your old screeching modems.
To standardize this communication protocol, folks came up with the Host Controller Interface (HCI) so you didn’t have to reinvent that protocol for every new chip. This was handy for people on the MCU side, since they could write firmware that worked with any wireless chip out there, and could swap out for a cheaper/faster one with minimal change.
Fast forward to the era of integrated MCU+wireless, where you had a little ARM or other lightweight processor plus a little radio, and the processor could run programs in a high-level API that abstracted out the low level wireless stuff. Plus, you could use the same radio for multiple wireless protocols, like BLE, wifi, ANT, etc. Nordic and TI were early adopters of this method.
Typically, it was the vendor’s own processor talking to their own wireless module, but they still implemented the full HCI interface and let it be accessed externally. Why? So if your design needed an extra beefy processor and used the MCU+wireless chip as a simple communication module, this would still work. The teeny MCU could be used to run something extra in parallel, or it could just sit idle. A typical example could be a laptop or cell phone. The little MCU is too small for everything else, so you pair it with a big chip and the big chip drives the little chip through HCI.
Sure, it would be cheaper if you just went with a basic ‘dumb’ wireless chip, as folks from CSR, Broadcom, and Dialog kept pointing out. But the market demanded integrated chips so we could have $10 activity trackers, fancy overpriced lightbulbs, and Twerking Santas (https://www.amazon.com/twerking-santa-claus/s?k=twerking+santa+claus).
For integrated MCU+wireless chips, most vendors didn’t release the super low-level firmware that ran between them. There was no need. It was internal plumbing. They exposed SDKs so you could control the wireless chip, or high-level Bluetooth/wifi APIs so you could connect and talk to the outside world in a few lines of code. These SDKs were unique to each vendor (like Nordic’s nRF Connect library, or TI’s SimpleLink SDK).
Then along came Espressif out of Shanghai, China with a combo chip (ESP8266) that offered processor + wifi and was so cheap and easy to program that it took the hobbyist market by storm. Oh, god… so many LED light strips, perfect for Christmas and blinky EDM lightup outfits (hello, Adafruit: https://www.adafruit.com/category/65).
Fast forward and Espressif drops the ESP32. A bigger, faster Tensilica Xtensa processor, with built-in flash storage, plus wifi, Bluetooth, and BLE in one place. Plus lots of peripherals, busses, and IO pins. Also, running FreeRTOS and eventually Arduino SDKs, and MicroPython. All for less than $5! It took off like a rocket. So many products. Plus, you could run them as little webservers. Who doesn’l love a little webserver in their pocket?
It’s gone through a few variations, including swapping out the Tensilica with an open-source RISC-V MCU, but otherwise it’s a massive seller and the gateway drug for most IoT/Smarthome nerds.
So along come these Tarlogic researchers, looking to build a direct USB to bluetooth library. This way, you can drive the wireless from, say Linux, directly. There are already BLE to USB stacks, but this one is giving access at the HCI level, in a C library. Handy if you’re doing research or developing drivers, but not the sort of thing your typical DIY person needs.
As part of their process, the researchers decide to dump the really low level ESP32 firmware and reverse engineer it.
A typical HCI implementation is a giant event loop that handles HCI opcodes and parameters. Host wants to talk to the outside world, it sets up some registers, configures the unique MAC address, then opens a channel and starts sending/receiving (hopefully without the modem screeching tones). There are typical packet encoders and decoders, multiple ISO/TCP layers, and the sort of thing that most people assume somebody else has gotten right.
For fancier implementations, there may be interrupt or DMA support. Sometimes, there’s a multi-tasking part under the hood so they can time-slice between wifi, bluetooth, and ble (aka Fusion or Coexistence support). Not that you should care. The internals of this stuff is usually nobody’s business and the vendors just include a binary blob as part of their SDK that handles things. The host systems just talk HCI. The wireless side talks HCI on the wired side, and wireless on the radio side. Everyone’s happy.
In the process of reverse engineering the low-level HCI blob, these researchers found a few extra undocumented HCI opcodes. They’re not sure what they’re for, but according to their presentation (https://www.documentcloud.org/documents/25554812-2025-rootedcon-bluetoothtools/) if my super rusty Spanish holds up, it has to do with setting MAC addresses and handling low-level Link-Level Control Protocol communications (https://www.ellisys.com/technology/een_bt10.pdf).
Now in an of itself, this is no big deal. ESP32s already let you easily set your own temporary MAC address (https://randomnerdtutorials.com/get-change-esp32-esp8266-mac-address-arduino/), so there has to be a way to override the manufacturer one. And LLCP management is a totally geeky low-level thing that the MCU needs when handling wireless packets. There are perfectly good reasons why the opcodes would be there and why Espressif may not have documented them (for example, they could be used only during manufacturing QA).
So the original presentation is a teeny bit of an exaggeration. Yes, the opcodes exists. But are they nefarious? Should we stick all our ESP32s inside Faraday cages? Is this a secret plan for the CCP to remotely control our lights and plunge the world into chaos?
As I said before, ONLY if there’s a secret as-yet-undiscovered wireless handshake that gives remote wireless access to these (or really, pretty much any other published HCI opcode). That presentation most definitely doesn’t claim that.
To see if there is a REAL backdoor, you should wait for an analysis from fine professional wireless debugging vendors like Ellisys (starting models run $30K and up), Frontline, or Spanalytics.
Incidentally, Tarlogic, the group that put out that paper have their own BLE analyzer product (https://www.tarlogic.com/es/productos/analizador-bluetooth-le/). They look to know their stuff, so they should know better than putting out clickbait-y hair-on-fire reports. But come on, who can resist a good CCP/backdoor headline? Will media run with this and blow it out of proportion? No way!
If you’ve read this far, you must safely be on your third drink or the edible’s just kicked in. Stop panicking, and wait until the pro sniffer and Bluetooth forum people give their opinions.
If it turns out there is an actual WIRELESS backdoor, then by all means, feel free to panic and toss out all your Smarthome plugs. Go ahead and revert to getting up and flicking on your light switch like a peasant. Have a sad, twerk-free Christmas.
But over a few undocumented HCI opcodes? Have another drink and relax.
Happy Sunday.
PS: controversy already up on wikipedia: https://en.m.wikipedia.org/wiki/ESP32
PPS: you may want to stock up on ESP32s for your light-up Christmas light project. Don’t be surprised if Espressif gets smacked with some hard tariffs or an outright ban, based on these ragebait headlines 🤷🏻♂️
Edit: DarkMentor offers a little more detail on the nature of the opcodes: https://darkmentor.com/blog/esp32_non-backdoor/
what a fantastic write up. thank you so much for taking the time <3
This isn’t a backdoor. Just a company trying to make a name for themselves by sensationalizing a much smaller discovery.
Seriously this. Every single IC which has digital logic contains some number of undocumented test commands used to ensure it meets all the required specifications during production. They’re not intended to be used for normal operation and almost never included in datasheets.
The other day someone posted in Canada community that Canada should stop using Tesla cars and import Chinese cars. I replied saying, “That’s like replacing one evil with another.” I was downvoted by a lot of people. I should’ve expected it cuz a lot of people have short term memory.
Because that’s not about privacy, that’s about the trade war. Retaliatory tariffs on US cars increase cost of cars for Canadians, as there are almost no car assembled in Canada. Reducing or eliminating tariffs on cars from China would lower cost of new cars for Canadians while keeping the tariffs up.
For privacy and security, not a single new car on the market is decent right now. That should be regulated, but that’s no concern for any politician at the moment.
Europe and its 50 car makers could also be considered instead of China…
Yes, but Canada had implemented 100% tariff on cars from China, following the US. That’s pre-trade war. The proposal is to lift that one.
Ah, I see. Thanks!
CCP has backdoor into every tech that comes out of China. It’s not about just privacy. They control democracies based on shaping narratives. They’ll utilize everything that democracy offers and use it against countries. They don’t have freedom of speech or press so they themselves are not victims of it. EVs are really just computers on the road. Flooding the market with Chinese EVs would just mean creating a massive free network on a foreign soil for them.
All cars are computers on the road at this point, not just EVs…
While technically true, that’s not what I meant. For example, Tesla Model 3 has AMD Ryzen chip. It is a full fledged computer CPU. Although my Toyota surely has a computer onboard, it’s nowhere close to this level of tech in the Tesla. EVs from China are at the same or higher level tech-wise compared to Teslas.
Summary: China is not a friend country. It’s a hostile country. Yes, we know.
But the news is… so is the USA to Canada now. A hostile country threatening to annex Canada and trying to cripple the economy as a way to achieve the goal. So either we slap 100% tariffs on US made cars, which would hurt Canadians, or we apply the same tariffs on Chinese cars, so reduce them from where they are at the moment.
All I meant was flooding the market with Chinese cars isn’t a huge security threat to the country. There’s another alternative. European cars.
There’s been a lot of that lately. Same here in New Zealand.
You dipshits, they’re both the bad guys now.
A lot of people are dumb. Or maybe because they feel offended because they are Chinese, but the reality is that every Chinese company is ultimately controlled by the CCP. If I was fighting a cold war, I would do the same. Sell compromised devices to my trade partners (AKA enemies) so I have leverage when I need it.
Or maybe because they feel offended because they are Chinese
I’m Chinese-American and I’m not offended. The tankies from .ml are
the reality is that every Chinese company is ultimately controlled by the CCP.
Yes.
But in the same way that every US company is ultimately controlled by the US Government. And every EU company by them. And every other country by their own government.
People act like traditional car manufacturers don’t exist anymore even though they all offer EV options…
deleted by creator
Jesus. Okay. So when you say, “being short sighted”, you don’t literally mean the geometry of their eyes is myopic. You mean it figuratively. Exactly like the person you are correcting clearly means it figuratively when they say “short-term memory”.
I’d like to know if this is just a firmware update or unfixable, but sadly this seems just an ad rather than news
It is not easy to determine how fixable this is. IIRC, the ESP32 has the wireless stack hidden from user space, and I am not sure if it is a blob included during link time, or if it is stored in a ROM of the chip. I do have the chips and the development enviroment in my studio, but (luckily) I decided to use a different chip for my project.
But I know there is a load of systems using either the ESP32 as their main processor, or as an auxiliary processor to add WiFi or BT capabilities, so this really is a big oh shit moment.
There is nothing to “fix”. Undocumented instructions have just been found in the silicon but they are not executable unless the ESP32’s firmware their owner flashed to give it a purpose uses them. No pre-2025 firmware that we know of uses these instructions, and they might turn out to be buggy so compilers might not adopt them. If they turn out OK, the documentation of the instruction set will need an update, and compilers will be able to take advantage of the new instructions.
Weird that they removed the reference to ESP32, one of the most common and widely known microcontrollers, from the headline.
It’s because the security company basically lied about this being a vulnerability, and probably opened themselves up to a lawsuit.
Please update the title of this post to mention the update
How so?
Idk maybe specify that it was determined to not be a backdoor. Right now it reads as anti-china fear mongering.
Thank you, I keep getting down voted because I said the same, but obviously other get it. Appreciate you and the sanity check!
You can edit post titles as well as content (even images!) on Lemmy.
The Chinese adding back doors into their software/hardware.
Say it ain’t so!
Like a PRISM for China, is every powerful country just backdooring each other?
Thats hot.
The rebuttal wasn’t as comforting as some are making it out to be. They seem to be more interested in the semantics of it not being a backdoor tied to a specific product, which appears to be true.
Rather it is a potential for vulnerability that exists in all wireless implementation, which seems to me to be a bigger issue.
The issue is where the undocumented commands are. They aren’t just allowing any old external person to send payloads to this.
It’s kind of like noticing that someone unexpectedly hid a spare key next to the door… On the inside of the house. Like, sure, maybe the owner would have like to know about that key, but since you have to be inside the house to get to it, it doesn’t really make a difference.
It’s a vulnerability where an attacker already needs code execution on the device/physical access.
If you have that you’re already compromised no matter what.
The biggest risk would be IoT devices.
That’s just the summary of the entire existence of IoT devices
I was reading someone else’s explanation and they said it’s the equivalent of every computer possibly having a backdoor because there is code in a computer that a bad actor can use. There are extra commands that could possibly be used for a backdoor if a malicious actor found a way to use those bits of code. It’s much less oh here is a security vulnerability that is being used and more of a if a robber breaks into our house which is possible they will rob us situation.
Fukin dmnit! I just spent the last several months fine tuning a PCB design supporting this platform. I have , what i believe to be my last iteration, being sent to fab now. I have to look i to this. My solution isnt using bluetooth, so i dont know if im vulnerable.
Its not a backdoor, you’re most likely fine.
Go for it. It’s a bullshit attention grab. No backdoor, just some undocumented vendor commands (which is the norm for virtually every chip out there).
The exploit requires physical access. It’s not exploitable in 99% of cases
Does anyone know where it is that we can find these new commands? I have an esp32 dev kit just a few feet away from me as i read this. It might be interesting to know what these new product “features” are.
One more reason to have actual open-source drivers instead of binary blobs…
Not the first time a backdoor was found on Chinese made hardware and it won‘t be the last time. Decoupling can‘t happen quickly enough.
Which government’s backdoors would you prefer?
“We know you have a choice in oppressive governments, so we appreciate you choosing ours.”
None of them, that’s why the only things in my house that connect to the internet are my computers, game consoles, and cell phone
Assuming you’re not joking here, if your computers are any way modern they almost certainly have a backdoor.
Obviously, but I trust my Linux mint laptop a hell of a lot better than my aunt’s XIPPLG branded wifi cat feeder that she bought off Amazon
You probably shouldn’t, check out Intel management engine and AMD secure technology.
From what I understand, the only way to mitigate the risks relating to IME or AMD PSP is to simply not have a computer in the first place. Like I’ve said elsewhere twice now, it’s worth mitigating some risks even if we can’t mitigate all of them. I don’t want the most advanced computing device in my home to be an astrolabe.
I guarantee all off those have components from manufacturers that a government could pressure for a backdoor.
You are correct, and it doesn’t change my stance at all. It’s still worth it to mitigate risk even if you can’t mitigate all risk.
Like, the fact that my 3d printer is already a fire hazard does not justify leaving a bunch of candles unattended
Not sure if joking or naive…
Like I said 6 hours ago, just because I can’t mitigate all of the risk doesn’t mean that I shouldn’t mitigate as much as I reasonably can.
My 3d printer is a fire hazard, but that’s no excuse for leaving a bunch of candles unattended.
Ah I missed the other comment, my client still had a cached view apparently. And definitely true regarding mitigation, your phrasing just read funny to me :)
I mean, most users here are browsing using a device with an AMD or Intel CPU, both with known backdoors. Not the first time a backdoor was found on American made hardware and it won’t be the last.
Gotta blame China to get upvoted on Lemmy.
Or use a precise title. It’s not a backdoor or a “backdoor”.
Yeah, one of those is factually correct and got upvoted…
You’re kidding, right?
I couldn’t find a list of devices. Anyone else find one?
The article is talking about the Espressif ESP32 micro controller (has Wi-Fi/Classic Bluetooth/BLE).
I don’t know if the variants of this chip also have the same vulnerability (my guess is yes). As someone who works on this chip, I’m interested in more discourse on this matter.
Yeah, I caught the ESP32 part and tried to search for what devices these chips were built into, but couldn’t find one. I was curious how widespread the flaw was - as in, what consumer or infrastructure devices they might be in.
Oh those kind of devices. Its very popular for hobbyists and self-designed devices or cheap IoT products. Don’t know the market presence outside Asia but its quite popular in India due to its low cost.
I’d also like to hear more. I have at least a dozen of these in my house.
That’s like saying “I want a list of all devices with ATmega328P.” Anyone can make a unique device with this chip as the processor, in fact I have. It’s a chip with an extremely low barrier of entry thanks to extensive documentation, lots of dev boards and libraries. Not as low as the 555 (lots of people’s first IC) but WAY lower than anything you’d traditionally consider a 32-bit CPU.
Anyway, even if you obtained the list magically, it would be of little use. To be clear: this is not an exploit. The chip just has more instructions than previously thought – instructions that you write into your program when building an ESP32 device. This can make some programs a little faster or smaller but you still need to flash them onto the microcontroller – using physical access, OTA (if you set it up in the existing FW) or some exploit (in someone’s OTA implementation, perhaps).
So your argument is what? We shouldn’t have a list because the chip is user friendly?
No. I’m saying you cannot have a complete list because the chip is user friendly. Look at all the “ESP32 project” results in the search engine of your choice if you want an incomplete list. Unlike say an Intel processor, you don’t need a contract with the manufacturer to make a device with the chip so not even Espressif has a list of commercial products that ship with their chip.
I will not stop you from building a list, I’d just not bother if I were you. There is no use of one resulting from this news. Suppose I told you “LOOK! This device’s firmware was compiled before they knew the program might be .1% more efficient with this instruction discovered in 2025!” – would that really change how you feel about the device? We live in an age of bloat; most software has way higher overhead that could be optimized away.
However, lots of people will fail to realize that, again, this is not an exploit so I’ll enjoy lower ESP32 prices for future home automation projects.
Dude, do I really need to pedantically qualify my question with “I would like a list of manufactured devices produced for sale with the chip already integrated, not hobbyist or ersatz devices in limited quantity? Nobody needs that, and a reasonable person would understand I’m not interested in what joe schmoe built in is garage.
C’mon, it’s like you’re looking for an argument. No shit we can’t have a list of every device based on your criteria, but we can reasonably expect to know what manufactured large-run devices do have it, and I think that’s a reasonable take on my question.
I agree that a list would be cool but I need to make sure that people know this is not a “WARNING! Avoid these bugged devices:” situation. Calling for a list increases unjustified panic. (Also, it looked like you didn’t understand the difficulties of listing all ESP32 products, which I was all too happy to be pedantic about.)
Am I oddly curious about the cheapest/most expensive/most popular retail ESP32 device? Yes.
Does this news increase/decrease the benefit of making such a list? No, it’s still way below the cost.
