this post was submitted on 11 Mar 2025
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[–] TheGrandNagus@lemmy.world 138 points 1 day ago* (last edited 1 day ago) (12 children)

This flaw allows attackers with local administrator privileges to bypass AMD's cryptographic verification system and install custom microcode updates on affected CPUs.

If you already have local administrator privileges, you have access to the system and its data anyway. Doesn't seem that critical a flaw. It doesn't even survive reboots.

Regardless, AMD has already issued a fix.

[–] Toes@ani.social 21 points 1 day ago* (last edited 1 day ago) (3 children)

Edit: seems I may be mistaken.

If I'm understanding this correctly this opens up the door to a serious type of rootkit.

It's not a matter of attackers having access to the data. It's that they have replaced your hardware with malicious hardware.

Additionally It can be trivial to gain administrative capacity on a personal computer. But in a regular case you can just reinstall the operating system. This would survive that.

[–] Dark_Arc@social.packetloss.gg 22 points 1 day ago* (last edited 1 day ago) (1 children)

On some level yes, but reading the article nothing persist between boots. This seems like a vulnerability that's really only that serious A if you don't apply AMDs patched micro code and B there's another vulnerability on your system that lets this persist between operating system reinstall/in the BIOS.

[–] kusivittula@sopuli.xyz 2 points 9 hours ago (1 children)

I'm having hard time understanding how the microcode patch is delivered. system updater or bios update? I'm fucked if it's a bios update cos my shitty gigabyte mobo won't detect the files

[–] lengau@midwest.social 1 points 3 hours ago

Your OS can load the microcode. Most Linux distros will load the latest microcode during boot. Some will even update the microcode when it gets the new microcode from the distro repositories. This facility exists specifically because motherboard vendors are terrible about providing updates.

[–] TheGrandNagus@lemmy.world 13 points 1 day ago (1 children)

That's not what this is about. It can't even survive a reboot.

[–] Toes@ani.social 4 points 1 day ago

Ah, thanks for the clarification.

[–] seeigel@feddit.org 7 points 1 day ago (1 children)

Aren't microcode updates erased after restarts?

[–] pivot_root@lemmy.world 5 points 23 hours ago* (last edited 23 hours ago)

As far as them being applied, yes. The loaded microcode is volatile.

They can kind of persist across cold reboots, but it relies on them being applied again at some point. The motherboard vendor can apply microcode updates during platform initialization before POSTing. Or they can be applied from EFI (modern equivalent of BIOS) before handing control to the kernel. Or they can be applied very early in the boot process by the kernel.

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