5 ms·

Tinycore was used at my last job to get around some frustrations of updating the embedded systems on the machines we made (which ran a full blown Linux system).

by mdtusz 6y ago

Tinycore was used at my last job to get around some frustrations of updating the embedded systems on the machines we made (which ran a full blown Linux system). We mailed customers USB drives that when plugged in would mount and start tinycore Linux, then write the new system to a parallel partition, reboot the machine, then run a few health checks. Some might say it's hacky (it is/was) but it worked pretty well and allowed for recovery of totally borked systems.

xwdv 6y ago
> We mailed customers USB drives- This would be a non starter for any security conscious client.
- mdtusz 6y ago
  Agreed that it's not a good practice security wise. This is what I argued against when the initial request was made (we also had over the air upsates) but it was interestingly the _most_ "security conscious" customers that had requested this - they specifically wanted us to mail them either replacement microSD cards (the disks on the machines) or USB sticks. The machines themselves verified the contents and we also offered a way for customers to download the images directly and verify, but most customers just opted for snail mail. /shrug. Several of these companies also had strict email attachment filters that we were instructed to get around by just appending `.allow` to the filenames. There was tons of this type of stuff that we encounted which really highlighted that corporate security at many companies is just theatre.
- plasticchris 6y ago
  Depends. If the image is signed/ encrypted it would be fine.
  - minitech 6y ago
    Until it switches to emulating a USB keyboard after you boot :)
- SahAssar 6y ago
  Shouldn't it be quite okay if using secureboot and the embedded system has locked down keys? I have no idea if they did that, but mailing USB keys should be fine with the right encryption or validation
  - shakna 6y ago
    If all you're looking to do is verify the USB storage, sure. But USB doesn't have to only be a storage device. You can include all sorts of other evils in a USB payload.
    - deleted 6y ago
      [deleted]
    - SahAssar 6y ago
      I read it as that Integrity and Confidentiality was the only factors here, so USBKill-style stuff (Availability) would just mean the machine was replaced, Integrity should handled by the boot process and Confidentiality should be handled by the embedded OS itself.
  - xwdv 6y ago
    It's not okay at all. You should not be plugging in a USB someone sent you in the mail straight into a machine on your corporate network. There is no chain of custody, an attacker could do many things to make it seem like the USB is legit as possible, until it isn't. Just a bad idea all around. There should not even be USB ports IMO.
    - SahAssar 6y ago
      Who said anything about a corporate network? You seem to be thinking that I said that it's okay to take random USB's and plug them into your laptop which I definitely do not. I read it as that Integrity and Confidentiality was the only factors here, so USBKill-style stuff (Availability) would just mean the machine was replaced, Integrity should handled by the boot process and Confidentiality should be handled by the embedded OS itself.

by mdtusz 6y ago

xwdv 6y ago

> We mailed customers USB drives- This would be a non starter for any security conscious client.

mdtusz 6y ago
Agreed that it's not a good practice security wise. This is what I argued against when the initial request was made (we also had over the air upsates) but it was interestingly the _most_ "security conscious" customers that had requested this - they specifically wanted us to mail them either replacement microSD cards (the disks on the machines) or USB sticks. The machines themselves verified the contents and we also offered a way for customers to download the images directly and verify, but most customers just opted for snail mail. /shrug. Several of these companies also had strict email attachment filters that we were instructed to get around by just appending `.allow` to the filenames. There was tons of this type of stuff that we encounted which really highlighted that corporate security at many companies is just theatre.
plasticchris 6y ago
Depends. If the image is signed/ encrypted it would be fine.
- minitech 6y ago
  Until it switches to emulating a USB keyboard after you boot :)
SahAssar 6y ago
Shouldn't it be quite okay if using secureboot and the embedded system has locked down keys? I have no idea if they did that, but mailing USB keys should be fine with the right encryption or validation
- shakna 6y ago
  If all you're looking to do is verify the USB storage, sure. But USB doesn't have to only be a storage device. You can include all sorts of other evils in a USB payload.
  - deleted 6y ago
    [deleted]
  - SahAssar 6y ago
    I read it as that Integrity and Confidentiality was the only factors here, so USBKill-style stuff (Availability) would just mean the machine was replaced, Integrity should handled by the boot process and Confidentiality should be handled by the embedded OS itself.
- xwdv 6y ago
  It's not okay at all. You should not be plugging in a USB someone sent you in the mail straight into a machine on your corporate network. There is no chain of custody, an attacker could do many things to make it seem like the USB is legit as possible, until it isn't. Just a bad idea all around. There should not even be USB ports IMO.
  - SahAssar 6y ago
    Who said anything about a corporate network? You seem to be thinking that I said that it's okay to take random USB's and plug them into your laptop which I definitely do not. I read it as that Integrity and Confidentiality was the only factors here, so USBKill-style stuff (Availability) would just mean the machine was replaced, Integrity should handled by the boot process and Confidentiality should be handled by the embedded OS itself.