uefi – Does Bitlocker provide a degree of protection from PKFail?

In the context of BitLocker, PCR 0 and other PCRs (such as PCRs 2, 4, 7, etc.) are used make sure the secure boot process is, well, secure!

BitLocker, (in its default configuration at least), checks these PCRs before releasing the decryption keys.

So where I am getting to is, if an attacker exploited a PKFail vulnerability to insert malware or modify the UEFI firmware, this would likely change the measurements stored in PCR 0 and possibly other relevant PCRs.

As a result, BitLocker would (or should) detect that the PCR values do not match the expected values for the state of a trusted system.
While it’d depend, in these situations BitLocker would typically prompt for a recovery key or code to unlock the system.

So yes, to answer your question, BitLocker definitely could stand between the PKFail vulnerability, or at least maker it much harder to be successful.