Re:AMI-Bios Sourcecode and UEFI Signing Key leaked?
by mjg59 on Friday April 05, 2013 @03:42PM
(#5500587)
"so we can assume that only BIOS setup application can touch BIOS flash"
Nope. Intel (at least) let you program the flash controller so it'll forbid writes from the OS but permit writes from System Management Mode. Load the firmware into RAM, hand a list of addresses to an SMM trap and wait for it to flash it. Entirely secure, as long as you're using signed images.
Nope. Intel (at least) let you program the flash controller so it'll forbid writes from the OS but permit writes from System Management Mode. Load the firmware into RAM, hand a list of addresses to an SMM trap and wait for it to flash it. Entirely secure, as long as you're using signed images.