3 ms·

People are surprisingly chill about BMCs as attack surface, eg Intel management features get a lot more scrutiny.

ilyt 4y ago
In proper environment the BMC is on its own dedicated NIC with no way to bridge to that network from the machine and only access from host machine being from root/admin account. And then there are people that just port-forward BMC ports to the internet as cheap remote KVM...
- Graziano_M 4y ago
  The operative word being "proper". In practice I see it accessible on the LAN far too often. The ipmi v2 protocol is so bad that if you just request to login with a known account name (which is probably 'admin') the BMC server will _provide you the password hash_ for you to crack at your leisure.
matja 4y ago
IMO because you can configure the BMC to use it's own dedicated NIC and network. That network should have no routing to the Internet and no production traffic, just BMC management. When Intel ME shares the NIC used for the OS traffic - that is far harder to secure.
- rbanffy 4y ago
  > That network should have no routing to the Internet and no production traffic, just BMC management. And no single computer with NICs on both the BMC network and one that can access the internet, hopefully. All it takes is one single mistake.
tinus_hn 4y ago
An important distinction is that one is a device you choose to add to the system, and the other is an offer you can’t refuse.
sys_64738 4y ago
You should never keep the BMC plugged into a network. Security 101.
- fulafel 4y ago
  That view is what I meant by my comment. IMO it's wrong - It's terrible product design that servers have network ports that will cause catastrophic failures unless carefully only connected to a special expertly secured un-network for fragile things.
  - sys_64738 4y ago
    It’s not wrong regardless of the BMC security. You don’t plug things into the network that don’t need to be plugged in. BMCs only need network access for servicing most cases.

ilyt 4y ago

In proper environment the BMC is on its own dedicated NIC with no way to bridge to that network from the machine and only access from host machine being from root/admin account. And then there are people that just port-forward BMC ports to the internet as cheap remote KVM...

Graziano_M 4y ago
The operative word being "proper". In practice I see it accessible on the LAN far too often. The ipmi v2 protocol is so bad that if you just request to login with a known account name (which is probably 'admin') the BMC server will _provide you the password hash_ for you to crack at your leisure.

matja 4y ago

IMO because you can configure the BMC to use it's own dedicated NIC and network. That network should have no routing to the Internet and no production traffic, just BMC management. When Intel ME shares the NIC used for the OS traffic - that is far harder to secure.

rbanffy 4y ago
> That network should have no routing to the Internet and no production traffic, just BMC management. And no single computer with NICs on both the BMC network and one that can access the internet, hopefully. All it takes is one single mistake.

tinus_hn 4y ago

An important distinction is that one is a device you choose to add to the system, and the other is an offer you can’t refuse.

sys_64738 4y ago

You should never keep the BMC plugged into a network. Security 101.

fulafel 4y ago
That view is what I meant by my comment. IMO it's wrong - It's terrible product design that servers have network ports that will cause catastrophic failures unless carefully only connected to a special expertly secured un-network for fragile things.
- sys_64738 4y ago
  It’s not wrong regardless of the BMC security. You don’t plug things into the network that don’t need to be plugged in. BMCs only need network access for servicing most cases.