> Here's the thing - the big vendors encrypt and sign their updates so that you cannot run your own microcode. A big discovery recently means that the authentication scheme is a lot weaker than intended, and you can now effectively "jailbreak" your CPU!
But there's no further details. I'd love to know about the specifics too!
I guess this one just slipped through the cracks?
They didn’t need a keyed hash at all, they needed a collision resistant hash.
SHA256 would have eliminated this vuln and it has a hardcoded “key” built into it.
Using a secret key for CMAC would not have been more secure, it would have just meant sophisticated hardware extraction of the key was required before this attack could be mounted.