6 ms·

Really though, if an attacker has unencumbered access to one’s device, all security goes flying out the window. The website is highly self-promoting.

jonhohle 6y ago
As another commenter pointed out, public charging or borrowed chargers are an issue. Think airport charging kiosks/counters. Maybe power over data connectors isn’t the best idea (I enjoy single cable docking, but an extra, magnetic power cable wasn’t that much more work).
- tptacek 6y ago
  Borrowed chargers aren't the threat model here; these attacks involve an attacker opening up your machine and reading the contents of the TB3 controller's SPI flash.
  - deleted 6y ago
    [deleted]
  - redactions 6y ago
    That isn't entirely accurate. The ability to clone a given device state gives access to any system which has authorized that cloned device. A borrowed thunderbolt device which is not the target machine may also be used to bypass security levels as a result. No need to open the laptop in that case. See section 3.1.1 and 3.1.3 in the report.
mappu 6y ago
> if an attacker has unencumbered access to one’s device, all security goes flying out the window 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.
- userbinator 6y ago
  This is rapidly starting to become less true Unfortunately, both for right-to-repair and actually owning the hardware you bought.
  - gruez 6y ago
    TPMs don't impede your ability to repair anything. Soldered ram is a hassle, but it's not any more malicious than soldered CPUs. It's a design choice, and tradeoffs had to be made.
    - mappu 6y ago
      > TPMs don't impede your ability to repair anything There are some stories like this: https://www.vice.com/en_us/article/akw558/apples-t2-security-chip-has-created-a-nightmare-for-macbook-refurbishers https://www.vice.com/en_us/article/akw558/apples-t2-security... It's suggested that many such devices might be stolen. But there will also be devices where the user forgot to wipe their data (or didn't know how); or devices that are only just damaged enough that you can't wipe the user data. Probably an official Apple store can refurbish them somehow, but that is the NOBUS / EARN IT argument.
      - p_l 6y ago
        Well, that's more an explicit T2 issue that goes beyond what is known as "industry standard" TPM. Apple just hates you a (big) bit extra.
  - p1necone 6y ago
    This kind of stuff shouldn't really theoretically have to affect repairability, but Apple seems to go out of their way to make sure that as much as possible gets bricked when you replace things.
- AshamedCaptain 6y ago
  Full disk encryption is still be broken, given a decade or 3. You might care about that risk or not, but the fact is still there. 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?
deleted 6y ago
[deleted]

jonhohle 6y ago

As another commenter pointed out, public charging or borrowed chargers are an issue. Think airport charging kiosks/counters. Maybe power over data connectors isn’t the best idea (I enjoy single cable docking, but an extra, magnetic power cable wasn’t that much more work).

tptacek 6y ago
Borrowed chargers aren't the threat model here; these attacks involve an attacker opening up your machine and reading the contents of the TB3 controller's SPI flash.
- deleted 6y ago
  [deleted]
- redactions 6y ago
  That isn't entirely accurate. The ability to clone a given device state gives access to any system which has authorized that cloned device. A borrowed thunderbolt device which is not the target machine may also be used to bypass security levels as a result. No need to open the laptop in that case. See section 3.1.1 and 3.1.3 in the report.

mappu 6y ago

> if an attacker has unencumbered access to one’s device, all security goes flying out the window 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.

userbinator 6y ago
This is rapidly starting to become less true Unfortunately, both for right-to-repair and actually owning the hardware you bought.
- gruez 6y ago
  TPMs don't impede your ability to repair anything. Soldered ram is a hassle, but it's not any more malicious than soldered CPUs. It's a design choice, and tradeoffs had to be made.
  - mappu 6y ago
    > TPMs don't impede your ability to repair anything There are some stories like this: https://www.vice.com/en_us/article/akw558/apples-t2-security-chip-has-created-a-nightmare-for-macbook-refurbishers https://www.vice.com/en_us/article/akw558/apples-t2-security... It's suggested that many such devices might be stolen. But there will also be devices where the user forgot to wipe their data (or didn't know how); or devices that are only just damaged enough that you can't wipe the user data. Probably an official Apple store can refurbish them somehow, but that is the NOBUS / EARN IT argument.
    - p_l 6y ago
      Well, that's more an explicit T2 issue that goes beyond what is known as "industry standard" TPM. Apple just hates you a (big) bit extra.
- p1necone 6y ago
  This kind of stuff shouldn't really theoretically have to affect repairability, but Apple seems to go out of their way to make sure that as much as possible gets bricked when you replace things.
AshamedCaptain 6y ago
Full disk encryption is still be broken, given a decade or 3. You might care about that risk or not, but the fact is still there. 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?

deleted 6y ago

[deleted]