Improper Initialization in go-tpm - CVE-2020-8918

 

Improper Initialization in go-tpm - CVE-2020-8918

Published: August 11, 2020 / Updated: August 21, 2020


Vulnerability identifier: #VU45878
CSH Severity: Low
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2020-8918
CWE-ID: CWE-665
Exploitation vector: Local access
Exploit availability: No public exploit available
Vulnerable software:
go-tpm
Software vendor:
Google

Description

The vulnerability allows a local authenticated user to read and manipulate data.

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'.


Remediation

Install update from vendor's website.

External links