37 ms·

The cons to that approach is the work it takes to design a BMC without knowing how the existing one is designed. Replicating all of the BMC behavior is hard.

The cons to that approach is the work it takes to design a BMC without knowing how the existing one is designed. Replicating all of the BMC behavior is hard. Differences in behavior might be easily spotted, whereas this can lie dormant until triggered. "Why does unit #4322 have a faster/slower ping response?" Oops, discovered!

kevin_thibedeau 8y ago
You don't have to redesign the BMC. Just repackage them with additional dice to take over I/O pins as needed.
- ams6110 8y ago
  Or just reflash the firmware. They should, but most people don't reflash the bios and BMC firmware when they install a new server. In fact I routinely encounter servers that are 5+ years in service that have never been reflashed.
  - dboreham 8y ago
    otoh you have to consider the probability that flashing the firmware will brick your server (p >> 0.0 in my experience).
    - ams6110 8y ago
      Absolutely, and I think that is why a lot of people are reluctant to do it. It's a fragile process and if you lose power or have a random cosmic ray hit at the wrong time it's game over.
  - mjg59 8y ago
    I know more than one vendor who's dumped firmware from BMCs to compare to the vendor image. Simply reflashing the firmware would be caught by this, an implant wouldn't.
  - basseq 8y ago
    Apple, at least, claims they do[1]: "As a matter of practice, before servers are put into production at Apple they are inspected for security vulnerabilities and we update all firmware and software with the latest protections." [1] https://www.apple.com/au/newsroom/2018/10/what-businessweek-got-wrong-about-apple/ https://www.apple.com/au/newsroom/2018/10/what-businessweek-...
    - ofrzeta 8y ago
      They surely don't write their own firmware for Supermicro boards? So "update firmware .. with the latest protections" means update from the hardware vendor?
  - cmurf 8y ago
    There's quite a lot of embedded firmware that isn't derived or controlled or affected by BIOS/UEFI firmware updates. e.g. Thunderbolt (PCIe) firmware.

kevin_thibedeau 8y ago

You don't have to redesign the BMC. Just repackage them with additional dice to take over I/O pins as needed.

ams6110 8y ago
Or just reflash the firmware. They should, but most people don't reflash the bios and BMC firmware when they install a new server. In fact I routinely encounter servers that are 5+ years in service that have never been reflashed.
- dboreham 8y ago
  otoh you have to consider the probability that flashing the firmware will brick your server (p >> 0.0 in my experience).
  - ams6110 8y ago
    Absolutely, and I think that is why a lot of people are reluctant to do it. It's a fragile process and if you lose power or have a random cosmic ray hit at the wrong time it's game over.
- mjg59 8y ago
  I know more than one vendor who's dumped firmware from BMCs to compare to the vendor image. Simply reflashing the firmware would be caught by this, an implant wouldn't.
- basseq 8y ago
  Apple, at least, claims they do[1]: "As a matter of practice, before servers are put into production at Apple they are inspected for security vulnerabilities and we update all firmware and software with the latest protections." [1] https://www.apple.com/au/newsroom/2018/10/what-businessweek-got-wrong-about-apple/ https://www.apple.com/au/newsroom/2018/10/what-businessweek-...
  - ofrzeta 8y ago
    They surely don't write their own firmware for Supermicro boards? So "update firmware .. with the latest protections" means update from the hardware vendor?
- cmurf 8y ago
  There's quite a lot of embedded firmware that isn't derived or controlled or affected by BIOS/UEFI firmware updates. e.g. Thunderbolt (PCIe) firmware.