CVE-2020-8918

11.08.2020, 19:15

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'.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	6.3 MEDIUM	LOCAL	HIGH	NONE	CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Google	CNA	6.3 MEDIUM	LOCAL	HIGH	NONE	CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
CVE	ADP	---				---

Base Score

CVSS 3.x

EPSS Score

Percentile: 2%

Vendor	Product	Version
google	go-tpm	𝑥 < 0.3.0

𝑥

= Vulnerable software versions

Known Exploits!

Common Weakness Enumeration

CWE-665 - Improper Initialization
The software does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.

References

https://github.com/google/go-tpm/security/advisories/GHSA-5x29-3hr9-6wpw