As its name suggests, LogoFAIL involves logos, specifically those of the hardware seller that are displayed on the device screen early in the boot process, while the UEFI is still running. Image parsers in UEFIs from all three major IBVs are riddled with roughly a dozen critical vulnerabilities that have gone unnoticed until now. By replacing the legitimate logo images with identical-looking ones that have been specially crafted to exploit these bugs, LogoFAIL makes it possible to execute malicious code at the most sensitive stage of the boot process, which is known as DXE, short for Driver Execution Environment.
So, does disabling the boot logo prevent the attack, or would it only make the attack obvious?
Can you even completely disable boot logos? When I select the option on my machine, it just shows the IBV’s (e.g. AMI) boot screen with its logo instead of the mainboard manufacturer’s logo.
Not necessarily, I guess. They’re talking about a firmware upgrade of sorts, and, at least on the machines I own(ed), performing it didn’t reset user settings (which disabling the logo is)
So, does disabling the boot logo prevent the attack, or would it only make the attack obvious?
Can you even completely disable boot logos? When I select the option on my machine, it just shows the IBV’s (e.g. AMI) boot screen with its logo instead of the mainboard manufacturer’s logo.
Usually you can, though the setting might be listed under something like “show diagnostic during boot”.
If you have access to replace the logo file, you probably have access to enable it as well.
Not necessarily, I guess. They’re talking about a firmware upgrade of sorts, and, at least on the machines I own(ed), performing it didn’t reset user settings (which disabling the logo is)