CVE-2020-8918: Improper Initialization

An improperly initialized ‘migrationAuth’ value in Google’s go-tpm TPM1.2 library can lead an eavesdropping attacker to discover the auth value for a key created with CreateWrapKey. An attacker listening in on the channel can collect both ’encUsageAuth’ and ’encMigrationAuth’, and then can calculate ‘usageAuth ^ encMigrationAuth’ as the ‘migrationAuth’ can be guessed for all keys created with CreateWrapKey. TPM2.0 is not impacted by this. We recommend updating your library to or later, or, if you cannot update, to call CreateWrapKey with a random value for ‘migrationAuth’.