What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-08-11 · updated 2026-06-17
• Weakness: CWE-665

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'.

Affected products

• Google LLC google/go-tpm library: before 0.3.0 — fixed in 0.3.0

How to fix

Upgrade to a fixed version: Google LLC google/go-tpm library 0.3.0. Check the vendor advisory for mitigations.

References

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

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