Vulnerability Description
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'.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Go-Tpm | < 0.3.0 |
Related Weaknesses (CWE)
References
- https://github.com/google/go-tpm/security/advisories/GHSA-5x29-3hr9-6wpwExploitThird Party Advisory
- https://github.com/google/go-tpm/security/advisories/GHSA-5x29-3hr9-6wpwExploitThird Party Advisory
FAQ
What is CVE-2020-8918?
CVE-2020-8918 is a vulnerability with a CVSS score of 6.3 (MEDIUM). 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 CreateWra...
How severe is CVE-2020-8918?
CVE-2020-8918 has been rated MEDIUM with a CVSS base score of 6.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-8918?
Check the references section above for vendor advisories and patch information. Affected products include: Google Go-Tpm.