Time-of-check time-of-use race condition in AMD's fTPM implementation

Summary

The Trusted Platform Modules (TPM) reference software may not properly track the number of times a failed shutdown happens. This can leave the TPM in a state where confidential key material in the TPM may be able to be compromised. AMD believes that the attack requires physical access of the device because the power must be repeatedly turned on and off. This potential attack may be used to change confidential information, alter executables signed by key material in the TPM, or create a denial of service of the device.