There are several ways to exploit LogoFAIL. Remote attacks work by first exploiting an unpatched vulnerability in a browser, media player, or other app and using the administrative control gained to replace the legitimate logo image processed early in the boot process with an identical-looking one that exploits a parser flaw. The other way is to gain brief access to a vulnerable device while it’s unlocked and replace the legitimate image file with a malicious one.
In short, the adversary requires elevated access to replace a file on the EFI partition. In this case, you should consider the machine compromised with or without this flaw.
You weren’t hoping that Secure Boot saves your ass, were you?
True, but this was the case without this finding, wasn’t it? With write access to the EFI you could replace the boot loader and do whatever you please.
In many of these cases, however, it’s still possible to run a software tool freely available from the IBV or device vendor website that reflashes the firmware from the OS. To pass security checks, the tool installs the same cryptographically signed UEFI firmware already in use, with only the logo image, which doesn’t require a valid digital signature, changed.
In short, the adversary requires elevated access to replace a file on the EFI partition. In this case, you should consider the machine compromised with or without this flaw.
You weren’t hoping that Secure Boot saves your ass, were you?
The idea is also that a compromised system will remains compromised after all storage drives are removed.
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Since the EFI partition is unencrypted, physical access would do the trick here too, even with every firmware/software security measure.
True, but this was the case without this finding, wasn’t it? With write access to the EFI you could replace the boot loader and do whatever you please.
Unless a proper secure boot + FDE setup is in place.
Yeah, if someone has write access to your boot partition then you’re kind of already screwed.
The worst part it persists through reinstalls (if i understood correctly)
This is also my understanding, at least of you keep the EFI partition.
It can outlast those too.
Boy do I love the future.
So if I have my computer set that it needs a sudo password for most changes am I good?
Yes, that’s my understanding. A normal user cannot do this. (And of course, an attacker shouldn’t not control a local user in the first place.)
Physical access is also a risk, but physical access trumps everything.
Thanks for the answer. Unless my dog learns how to code I think I’m safe from anyone getting physical access
As a hacker imma start teaching dogs to code as part of my breakin process, sorry bud
Unless they find another way to escalate privileges… A bug, a random binary with suid, etc