CVE-2020-8918TPM 1.2 key authorization values are vulnerable to a TPM transport eavesdropper
- 6.3MediumCVSS base score
- 0.18%Exploitation in 30 daysEPSS · top 92% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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'.
Timeline
ID reserved
By Google
- 6 months later
· 6 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GoogleCNA (assigner) | 3.1 | Medium6.3 | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
| NVDNVD · Modified | 3.1 | High7.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.18% · top 92% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.3.
Affected products
Google LLC · google/go-tpm library
- affected stable – < 0.3.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/google/go-tpmGHSA-5x29-3hr9-6wpw (opens in a new tab)
References
References1
- https://github.com/google/go-tpm/security/advisories/GHSA-5x29-3hr9-6wpw (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2022-0847 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-5x29-3hr9-6wpw (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2020-8918)Record last updated .