Extracting Firmware from Embedded Devices (SPI NOR Flash) ⚡
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- เผยแพร่เมื่อ 26 เม.ย. 2024
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One of the first things you have to do when hacking and breaking embedded device security is to obtain the firmware. If you're lucky, you can download it from the manufacturer's website or, if you have a shell, you can just copy it over to your computer.
But what if none of these options are available?
In this video, we will show you how you can connect directly to a NOR flash chip with the SPI protocol to dump the firmware and find your vulns, even if off the shelf tools don't work!
00:00 Intro
00:40 Technical Introduction
01:55 Flash Memory Types
03:51 NOR Flash
06:25 SPI Protocol
07:55 Our Training
09:27 Logic Analyzer
12:04 How SPI Works
13:53 Firmware Extraction
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~ Flashback Team
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Really informative video, thank you! Sadly I see there will be fewer and fewer devices "hackable" in the near future as more and more manufacturers (especially of routers / e.g. DOCSIS 3.1) start using hardware based encryption technology for their ROM. With little to no possibility to ever read extracted data. What do you think about this?
We see more vendors using all kinds of firmware protection in their devices but still quite a lot of this can be bypassed. We actually cover this topic and how to bypass firmware encryption in our training.
Few examples that we have used or seen on real life devices:
* Firmware upgrade is encrypted but there is decryption binary on the device. All you have to do is reverse or emulate the binary to decrypt outside of the device.
* Firmware upgrade is encrypted but the actual firmware on the flash is not.
* Firmware is encrypted but you can get access to a running system.
* Firmware stored on flash is encrypted but encryption keys are not stored properly or are cached.
* Firmware is protected by read-only fuse but it would be possible to bypass that check and extract firmware.
* Side channel attacks allow to reveal encryption keys
But if vendor did a really good job and encryption material is stored in hardware and it can't be retrieved easily or firmware can't be decrypted, you have to level up - find a zero day vulnerability using black box techniques, which we also did on few occasions. It's always a matter of how much time and energy you can invest on a target.
@@FlashbackTeam what about qualcom chipsets ? can we hack it , because they lock the cpu and gpu clock. trustzone and other hardware controles the clock frequencies now , any way to hack it ?
smells like scriptkiddy in here
Such encryption is inherently flawed because the mechanism to decrypt must reside within the device itself; so there's always - at least in theory - going to be a way to extract the decryption key from the device. I'm pretty sure the more common this becomes, the more people will find ways to do exactly that.
@mr wpg Spoken like a true engineer. :)
Everything is explained clearly without wasting time or over-explaining. Well done.
That's exactly what I was going to say!
Please never delete this video, it's very helpful.
Very helpful for someone like myself just beginning to understand this stuff. Explaining the function and description of terminology is something i would normally have to do significant research for.
Damn this channel is so underrated.. just stumbled upon this while scrolling but definitely gonna stay for more .. Thanks for explaining this so well!
Thank you for your kind words. We are working on a new video that we will release in the coming weeks. We are very excited about it and it's going to be just awesome! This time more into vulnerability research and exploit development.
Your videos are the best! Please don't stop making the tutorials! Thank you.
What an entertaining channel! I've been watching some pluralsight and udemy courses recently, and I wish the presenters of those courses had the same style and pace as you guys. You are always interesting. Well done!
What a beautiful work!. Thank you for sharing your time and effort.
Perfect! Not to simple, not to complicated, with practical information.. Thank You
wow.... this is one of the most fascinating videos I've ever seen on YT....
Love these videos flashback team!
Thanks for this content, it is really well explained.
That's nice. Great video brother!
I just discovered your team, thank you so much for this interesting content!
FYI: most routers are linux-based (e.g. Huawei created their own distro called "Dopra"), which means if you lucky then the flash isn't encrypted and you can mount EXT filesystem from it
They usually add a header to the firmware that you need to strip out.
@@superslammer you're right! I did figured out weeks ago on my old huawei router
@@KangJangkrik linux to the rescue :D
Thanks for this content we can see al the time you have spend to make this incredible video !
Damn this channel is a hidden gem
impressive stuff guys. I'm just getting started with electrical engineering. I've been seeing that a lot of intelligence agencies like to play games with each other at this level. It's all really fascinating.
So dope that you guys put this out for free. If it was near me I would totally attend your in-person training. A paid virtual event would also be awesome.
We will be having both onsite and online trainings this year.
More information than from my technical degree in a few minutes
This is really interesting, thank you for this content. Have you ever thought about analysing the SONOS smart speakers? I know that there is a lot of people interested in understanding these in order to be able to analyse the protocols used so that they can add their own DIY builds like with a raspberry pi to the network
Yesss! I love to see you back!
Pleasee consider to upload more often
This channel is a treasure..
You should consider offering a recorded ‘on demand’ version of the course. I would buy it!
Interesting. Look forward to more content.
WOW mind blow stunmbled on this channel and glued to the screen...
thank you so much, Ive learnt alot from you in this video.
Truly impressive!
lol 😆🤣 9:55 oh Jesus got me cracking but all jokes aside this is one of the best well explained video on firmware extraction thanks
Ima download it thanks for sharing!!
Very nice simple and clean
Pls more videos ! Thats awesome
Great work!
Thank you, it works perfect!
great video !
Very good hacking ! Nice job guys. I hope one day I can do your training session
He's so good at what he does.
Nice info, thanks :)
I DEFINUTELY subscribed to this channel! F'ing quality bro!
I'll be promoting you guys in all the forums I'm in ... STARTING with this video!!
Lmao! Alright you got me with the Saleae joke.
hanks lot Sir.. You helping us..
I was waiting so bad for a new video! Great
Interesting. Thanks!
Please regularly upload such a knowledgeable videos. After long time I am watching your videos. Love from India 🙏
I'd propose that while getting firmware images from a manufacturer's website is the easiest path, it still leaves the question of whether the firmware on the device is the same that is currently flashed to the device. While higher risk, and effort, pulling the firmware from the device is the most deterministic way to get the current firmware.
Yes, that's a very good point. Plus you can find extra info, i. e. Device's config that is not part of the firmware downloaded from vendor.
that's really good!
I applaud your patience. My method of IoT “hacking” involves only two steps. Search, then destroy. I may start posting my handywork on another platform.
Nice! Used a similar process a few years back for some NAND flash. Didn't know about the hydrabus back then though. Instead I wrote a plugin using the older version of Saleae's SDK to dump the data of read commands to a binary file. Then had to do a little post-processing to get rid of the error correction codes that NAND has to transmit. Glad to see content showing an approach to the process!
In the past we were using Teensy with custom code to dump NAND Flash. Worth giving it a try too! But of course the most efficient is to simply use a programmer, but less fun.
@@FlashbackTeam Lots of lessons learned! I don't think I knew what a programmer was at the time. We relied on the SoC's bootloader to copy the file system from flash and we just copied the bus. Asking the flash to kindly show us its memory would have definitely been more elegant 😂. Luckily the flash data at rest wasn't encrypted!
Great resource
this is some good quality stuff (even if i dont understand half of it lol)
Quite interesting video!. Im thinking to apply this tecnique to a grandstream fxs voip adapter: i have two, one working properly another bricked (extract ok -> write bricked). It seems a corrupted flash , so it worth the effort
Muito bom !!
Obrigado.
Tudo de bom para ti Pedro e também para o Radek.
I particularly like the sound quality during the NOR description!
Thank you! We are slowly improving our recording hardware and editing techniques :-)
Very Nice!
Excellent! used for hikvision
Excelent video.
You're my Master 🌹❤️
Hello, Flashback.
I have a question. 16:59 and 17:42
The datasheet told us to use the Rising Clock. but why? Saleae told us the data use Falling Clock.
well Done! Very helpful, like from Pakistan
wow...nice!
Amazing Video, Any time coming to India for training?!
I understand the general idea but executing it is a different story. I'm no hacker but this is very informative in itself. 👍
Wow, it was cool to see how embedded devices get hacked as for man who is interested in embedded and IoT. Thanks for video
thx dude
This is really cool! I wanna dump the firmware of my e-scooter to hack it a bit, I didn't realize it could be that trivial :-) hopefully I get lucky and I can read/write firmware that easily!
We're happy you got inspired. Keep in mind that it all depends on where a firmware is stored. If it's external flash it is relatively easy. If firmware is stored within SoC/MCU then it won't be that easy as most likely there will be read protection that would need to be bypassed first.
@@FlashbackTeam That's exactly what I was thinking - I use MCUs for work stuff, and it's not necessarily that easy to dump their firmware given their flash is on-chip! I'm just hoping I might get lucky with the e-scooters one way or another ; if not dumping existing firmware to reverse it and tweak it, then perhaps finding an open source reimplementation that I could flash onto the chip, or making a new board myself if I have to (the main control board in that scooter isn't the one doing power distribution to drive the motors, so it's not unrealistic to just make my own, just will take more time...)
pięknie, mega wideo ;)
Iv just found this channel though a other channel and brother learning curve on both wow thinking 🤔 ik what I want to do
Jucy info good work
Great video! Hey, is there a less expensive alternative to the Saleae Logic Analyzer that will achieve similar results?
There are some Chinese clones of Saleae, such as this one: www.sigrok.org/wiki/MCU123_Saleae_Logic_clone
Unfortunately Saleae doesn't sell the small 4 channel cheaper version that we show in the video any more. But keep in mind this version can't sniff high speed protocols like USB, while the other Saleae big boys can.
If you're doing it as a hobby, I guess the Chinese clones work well enough. But if you are going to take this seriously, we highly recommend buying a proper Saleae.
How extract firmware from a altera device with jtag? Great work!
I love you !!
Reassembling the memory from just sniffed traffic is feasible... But you only get the parts that are actually read. Might have to exercise the device a little so you get better coverage. Boot sequence might be enough to get a foot in.
great video, I have a question though , I did EEPROM dump from a speedometer cluster quite a few times, nothing illegal, since I'm into car repair business , some vehicles come with bad clusters and guy would bring another one from a dump and asked me to program the mileage that would correspondent to vehicle being repaired , now there is a program that once you got your dump would calculate new hex value for new given mileage , however this generator software only works for certain vehicle brands, I wonder why same hex value for a given number gets interpreted as a different number in terms of mileage on different eeproms ? thanks
Can you do it with a stm8s with Read-Out Protection? Im suffering trying to extract firmware from a Sinotimer three-phase protector
very informative video !
Amazing ....
¡Gracias!
Thank you very much for supporting our channel!
Really great video.. I've never done this, but have most of the tools and have been thinking of trying it just for fun.. I'm curious though - When you are powering that EEPROM from the clip, I'd be worried that I'd also be backfeeding power to the rest of the circuit, and potentially causing it to boot up, which might cause the MCU to start taking over the SPI bus.. Is there some way to guarantee you're only powering the memory that I'm missing, or is this really not as big of a problem as I am envisioning? Could techniques like finding the reset pin on the MCU and holding it low to prevent booting perhaps be a good workaround? Any other hints? How much experience is needed before I shouldn't expect to be completely lost in one of your in person training classes!?
Hi. Thanks for your feedback. Very interesting questions.
1) From our experience, some boards would indeed be powered-up when we connect to the chip. Keep in mind, that we are supplying 3.3V so I assume it really depends on the board design. However, we didn't find it a big of an issue for us. When this happens, we usually wait a bit to increase the chance that the SPI bus is free. On many targets, after the boot process is finished and firmware placed in memory, there is much less data being fetched by a CPU compared to a booting stage. We just start our dump at that moment. Also, SPI protocol has that CS line which selects a chip. So all in all, it's not big of an issue for us. But keep in mind we are not electronics engineers, we are just hacking those devices using whatever works for us.
2) The reset pin technique is a very good idea. In fact we used it in the past on one of the target but for a different purpose.
3) If you can interrupt boot sequence, for example by entering bootloader menu, there should be very little interaction with the chip.
4) So far in most of the cases we didn't have to desolder SPI chip to read content from it. Usually in-circuit and it just works. It is on a contrary to NAND TSOP-48. Those almost never work in-circuit and we need to desolder it.
5) As for the training, it's an intermediate level course. The hardware part is on first day and we always use hw hacking only for the purpose of getting the firmware or enabling debugging. Sort of a first step in the chain. Then on the remaining days we move on to vulnerability finding and exploitation. For that reason, a student needs to have a good linux command line knowledge and some basics of reverse engineering and C knowledge. But we never leave anybody behind.
which MCU
What is the name of the blue clip you're using to connect to the legs of the chip?
They are called Ponoma clips, and they're much more expensive than "normal" clips, but well worth the extra money.
Yeah, the normal clips are garbage. I'll check the Ponoma clip then!
You're the first one I've done across that mentioned the name of the better clip so now I'll be able to actually buy one xP
Finally found something useful information 🤠
thanks for the video. I ve got one question. What is flash is internal to the MCU, so how would it be possible to extract the firmware ? Thank you.
In such cases a target specific attack is required. It would need a separate research and maybe use different techniques like glitching.
So to glitch an SPI flash we have to figure out SCLK and then run a brute force to figure out time to glitch
Thx
Cool! I'd like to see more of the data extracted and what you can do with it. Translate to English so to speak.
what about the microcontroller used in scientific calculators ??
what was the board used to show the tutorial
You mean the microcontroller that we used to connect to a router? It's called hydrabus.
I remember encountering myself with a "Flashrom repository" or something like that. It had tons and tons of Flash Chips to look at, so much that I got overwhelmed with the information.
It is great that nowadays reverse engineering is becoming something more common.
Greetings from Paraguay.
nice
What about reading firmware out of chips with included flash like STM32F4? They are often read-out protected against firmware extraction.
You are right. In most of the cases, microcontrollers with internal flash are shipped with read protection. In those cases different techniques are needed. Unfortunately they are not-standardized and attack path would need to be unique per MCU family. One of the approaches here could be using fault injection to attack bootloader / early routines that checks a fuse state.
Possibilities to going further into this for us? I need extract a firmware from uController too...
Did you recently speak at Shmoocon about this, but on a higher/conceptual level? Someone with a similar accent did. Regardless, this video is what I was hoping for!
We are glad you like it. We didn't speak at Shmoocon so it must have been somebody else.
I found in my Rog Strix laptop some interface called JDEBUG2, which has 15 pins. Not really an embedded device, but I wanted to know more details on this interface and whether I can have some commands to show me laptop's diagnostics :).
You can use a signal analyser like the one we show in the video to try and understand what it is. With that number of pins and name, a quick (probably wrong) guess would be JTAG. However, we would be very surprised if JTAG is enabled on a laptop shipped to the public!
@@FlashbackTeam ok, but do you have any info about what could JDEBUG2 stands for? The only thing I can research on google is asus related posts and jdebug on the java JVM.
I will try to crossmatch jtag and jdebug for a test on a new search quest :).
Hard to tell what sort of debug interface it could be. I think best is if you find a schematic for this laptop. There should be a diagram and description of the interface. Maybe try to ask on some laptop repair forums / YT channels?
@@DamjanDimitrioski JDEBUG2 is JTAG Debug (header number 2) :) It's a debugging interface for troubleshooting eventual motherboards issues.
@@ioanbustean7442 thanks, any specific specification url or more info about header number 2?
How does it work this ID with a low-stage firmware in the Chinese devices like TP-LINK etc.? This same or manyway?
Nice video. Sad it used such a proprietary board, but thankful that board is open source.
I see lots of SOIC-8 flash chips like at 9:56 with a second set of pads at 90 degrees to the SOIC-8. I'd love to know what's going on here because it seems to common. I assume it's for some kind of SOIC-16 flash chip instead of the '8 but I've never heard anyone talk about it.
send pic
@@phr3ui559 06:27 09:56
Amazing! Is there any plans to come to Brazil? Obrigado!
Hi Fabiano, if the right opportunity pops up, for sure. We both would love to go there, we haven't been yet!
@@FlashbackTeam Thanks
@@fusca14tube de nada meu irmão ;)
How do you exactly what the functions are, in FlashRom?
can hydrabus use to communicate with JTAG?
It can, with openocd. It also supports JTAG pin discovery.
Dear Santa.. I know what I want for Christmas. :D
Good
Why are you not at BlackHat?! This was excellent video!