4 ms·
Platform Secure Boot will measure the firmware into the TPM, so if an attacker modifies the firmware then yes, it'll be detectable. The microcode is signed so a
by mjg59 2y ago
Platform Secure Boot will measure the firmware into the TPM, so if an attacker modifies the firmware then yes, it'll be detectable. The microcode is signed so any attempt to modify it will simply result in the CPU booting with its ROM-based microcode.
- creer 2y agoWe'll get more detail tomorrow from Defcon - as to where the flaw is located. Apparently something in that neighborhood allows persistence - and for the attack not to be reported.
- mjg59 2y agoThe shape of the flaw seems pretty clearly described in the abstract - it's the ability to either modify the contents of the locked SMM memory regions (and so get arbitrary code execution there), or trigger SMM execution of code outside the SMRAM region. Either way, SMM vulnerabilities aren't new, and the capabilities associated with them are pretty well understood - what's different here is that the vulnerability is apparently in the CPU rather than the firmware, and so everyone's affected no matter who their firmware vendor is.