Additionally, regardless of the OS you run, Macbooks aren't affected by the Security Level/SPI flash hacks they came up with to disable Thunderbolt security.
https://christian.kellner.me/2019/07/09/bolt-0-8-with-suppor...
"THUNDERBOLT IS HOPELESSLY INSECURE AND BROKEN!!"
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* except on 90% of computers shipping with Thunderbolt.
Windows PC makers were much later to TB3 and even now only ship it on a small percentage of their computers. I'm not even sure there is a Linux out of the box system with TB3 support.
> All the attacker needs is 5 minutes alone with the computer, a screwdriver, and some easily portable hardware.
Just started reading, but the comparison is already a little bizarre. It almost seems like the digital version of "This murderer is on the loose and you're in danger! He doesn't need to inject poison into your food. All he needs is just 5 minutes in front of you with a knife!"
To use your analogy, in the former case, the murderer poisoned your food at the grocer's, and you unwittingly dose yourself when you make your meal. In the latter case, the murderer spends time getting to know you and letting you trust them, and then one day, when you go to the bathroom, they come in and shoot you like Vincent Vega.
[0] https://en.wikipedia.org/wiki/USB_flash_drive#BadUSB
That being said, malicious hardware is a problem. A hacked phone charging terminal at the airport could certainly be a serious problem if there are enough vulnerabilities in the USB stack.
People frequently say this, but never really explain it. As far as I can tell, it translates to "Nobody cares about physical security" - except it's clear that people /do/. Things like Boot Guard are only really relevant to physical attacks. DMA protection in firmware is only really relevant to physical attacks. It's extremely obvious that the industry is attempting to avoid short term physical access to a device being sufficient to compromise it, and research that demonstrates that it's still possible is valuable.
Let's break down each of the "vulnerability".
1. "However, we have found authenticity is not verified at boot time, upon connecting the device, or at any later point." This is actually false. Like, the author either didn't experiment properly or is lying/purposely misleading you. The firmware IS verified at boot for Alpine Ridge and Titan Ridge (Intel's TB3 controllers). They aren't for older controllers which does NOT support TB3. When verification fails, the controller falls back into a "safe mode" which does NOT run the firmware code for any of the ARC processors in the Ridge controller (there are a handful of processors where the firmware contains compressed code for). I'm willing to bet the author did not manage to reverse engineer the proprietary Huffman compression the firmware uses and therefore couldn't have loaded their own firmware. Because if they did, it wouldn't have worked. Now the RSA signature verification scheme they use to verify the firmware does suffer from some weaknesses but afaik doesn't lead to arbitrary code execution (on any of the Ridge ARC processors). I would love to be proven wrong here with real evidence though ;)
2. Basically the string identifiers inside the firmware isn't signed/verified. This has no security implications beyond you can spoof identifiers and make the string "pwned" appear in system details when you plug the device in and authenticate it. Basically if you've ever developed custom USB devices you can see how silly this is as a "vulnerability."
3. This is literally the same as #2.
4. Yes, TB2 is vulnerable to many DMA attacks as demonstrated in the past. Yes, TB3 has a TB2 compatibility mode. Yes, that means the same vulnerabilities exist in compatibility mode which is why you can disable it.
5. This one is technically true. If you open the case up, and flash the SPI chip containing the TB3 firmware, you can patch the security level set in BIOS and do stuff like re-enable TB2 if the user disabled it. But if I were the attacker, I would instead look at the SPI chip right next to it containing the UEFI firmware and NVRAM variables (most of which aren't signed/encryption in any modern PC).
6. SPI chips have interfaces for writing, erasing, and locking. If you have direct access to the chip you can abuse these pins to permanently brick the device. Here's another way: take your screwdriver and jam it into the computer.
7. Apple does not enable TB3 security features on Boot Camp. I guess this one is vaguely the only real "vulnerability" although it's well known and Apple doesn't care much about Windows security anyways (they don't enable Intel Boot Guard or BIOS Guard or TPM or any other Intel/Microsoft security feature).
Not that it matters but my personal experience with TB3 is that I've done significant reverse engineering of the Ridge controllers for the Hackintosh community.
Boot Guard makes that impractical in most cases. The point here is that on machines that don't implement kernel DMA protection, you're able to drop the Thunderbolt config to the lowest security level and then write-protect the Thunderbolt SPI so the system firmware can't re-enable it, making it easier to perform a DMA attack over Thunderbolt and sidestep the Boot Guard protections.
This isn't a world-ending vulnerability, but it's of interest to anyone who has physical attacks as part of their threat model.
Hi, I'm the author of Thunderspy. I'll restrict myself to answering your first point.
There appears to be a misunderstanding. The first vulnerability we found is 'Inadequate firmware verification schemes'. We do not claim a general ability to run arbitrary code on the Thunderbolt controller. Rather, we found that the signature does not cover the data in the SPI flash essential for Thunderbolt security. We've released tools that allow you to modify the SPI flash contents without changing the parts of the firmware covered by the signature (see [1], exploitation scenario 3.2.1 in the report [2], and the PoC video [3] that matches the latter scenario). This is how it is possible to read and modify device strings, uuid, and secret values. The steps for doing specifically the latter are detailed in exploitation scenarios 3.1.1, 3.1.2 and 3.1.3. Please let me know where you got stuck.
[1] https://github.com/BjornRuytenberg/tcfp [2] https://thunderspy.io/assets/reports/breaking-thunderbolt-se... [3] https://www.youtube.com/watch?v=7uvSZA1F9os
The section "3.1.3 Cloning victim device including challenge-response keys (SL2)" does not require flashing the victim system, it only requires reading flash from victim device which seems lesser hurdle.
I'm not going to feel safe charging with a public use charger until I find some way to insure only power and not data is making it to my device. Even POE feels like it's safer than modern peripheral standards right now.
(I admit this might not be perfectly linked to the article, it's just a need I've felt for a while but I can't seem to buy a solution for.)
If you ever plug in a charging cable and get the prompt, you know something is wrong.
https://www.vice.com/en_us/article/akw558/apples-t2-security...
I guess MacBook resellers sometimes get computers where the password has been set and they can't get into the computers. I imagine they would be motivated to find anyway they can to unlock the computers.
I thought that this had changed with USB-C?!
The website is highly self-promoting.
This is rapidly starting to become less true - full disk encryption is everywhere, backed by hardware TPMs; the Lockdown LSM prevents root from owing the boot chain; devices with soldered RAM are functionally immune to cold boot attacks.
There are still things an attacker can do - put a hardware keylogger on the keyboard wires, a skimmer on the fingerprint reader - but that requires future input from the victim. It is feasible today to defend against a physical attacker if you have the right hardware upfront and don't use it after the attack.
Unfortunately, both for right-to-repair and actually owning the hardware you bought.
The point still is that if the attacker has unencumbered access to your device then indeed _further_ use of the device is unrecommended to say the least. It doesn't matter if you had or did not have full disk encryption. It does not matter if you had or did not have Thunderbolt.
An extremely low tech solution would be to place a smallish and tactically hidden camera on the chassis, you don't even need the screwdriver for that. And it just happens all the time on ATMs and I'd bet that like on ATMs it would fool a shitton of people.
And this story is precisely about the type of attack that "requires further user input" -- what would be the point of requiring Thunderbolt at all in the first place if you already have the system in pieces?
