If I’m understading what I’ve been able to glean about this just by googling, it looks like the vulnerability is in certain tools that Microsoft has decided to sign with some of its UEFI secure boot keys. It’s not a vulnerability in your UEFI firmware itself, except insofar as your UEFI firmware comes already configured to trust Microsoft’s certificates. So even though the vulnerability isn’t in your UEFI firmware per se, the fix will require revoking trust to keys that are almost definitely pre-installed in your UEFI firmware.
No, it means that Linux systems also need to blacklist the keys in their UEFI firmware. I don’t know if distros push updates for those blacklists or if you have to do it manually.
As drspod said, no, Linux is not invulnerable. For Linux users using legacy BIOS boot or using UEFI but not secure boot, this vulnerability doesn’t make anything any more insecure than it was already. But any user, Linux or Windows, who is affected by this vulnerability (which is basically everyone who hasn’t revoked permissions to the Microsoft keys in question), if they’re using secure boot, no they’re not. (That is to say, they can no longer depend on any of the guarantees that secure boot provides until they close the vulnerability.)
If I’m understading what I’ve been able to glean about this just by googling, it looks like the vulnerability is in certain tools that Microsoft has decided to sign with some of its UEFI secure boot keys. It’s not a vulnerability in your UEFI firmware itself, except insofar as your UEFI firmware comes already configured to trust Microsoft’s certificates. So even though the vulnerability isn’t in your UEFI firmware per se, the fix will require revoking trust to keys that are almost definitely pre-installed in your UEFI firmware.
Ever looked at the list of pre-revoked certs that comes on a new mobo? It seems like this is not a new flavour of fuckup.
Does that mean Linux is invulnerable?
No, it means that Linux systems also need to blacklist the keys in their UEFI firmware. I don’t know if distros push updates for those blacklists or if you have to do it manually.
As drspod said, no, Linux is not invulnerable. For Linux users using legacy BIOS boot or using UEFI but not secure boot, this vulnerability doesn’t make anything any more insecure than it was already. But any user, Linux or Windows, who is affected by this vulnerability (which is basically everyone who hasn’t revoked permissions to the Microsoft keys in question), if they’re using secure boot, no they’re not. (That is to say, they can no longer depend on any of the guarantees that secure boot provides until they close the vulnerability.)