CVE-2020-8918

TPM 1.2 key authorization values are vulnerable to a TPM transport eavesdropper

HIGH
7.1
CVSS Score
Published: August 11, 2020 at 06:35 PM UTC
Updated: June 17, 2026 at 03:27 AM UTC
1 product affected across 1 vendorGo Tpm

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Severity
HIGH7.1
Exploit prediction
EPSS 0.2%

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.3.0stable ≤ v < 0.3.0stable
Affected range stops below 0.3.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-665

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