CVE-2020-8918 MEDIUM

CVE-2020-8918: TPM 1.2 key authorization values are vulnerable to a TPM transport eavesdropper

Vendor Google Llc
Product google/go-tpm library
Weakness CWE-665
Published August 11, 2020
Last update August 4, 2024

CVSS base score

6.3/10
Attack vector Local
Attack complexity High
Privileges required None
User interaction Required
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

What the vulnerability does

01Description

An improperly initialized 'migrationAuth' value in Google's go-tpm TPM1.2 library versions prior to 0.3.0 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 0.3.0 or later, or, if you cannot update, to call CreateWrapKey with a random 20-byte value for 'migrationAuth'.

Key dates

02Disclosure timeline

August 11, 2020 CVE published
August 4, 2024 Record updated