CVE-2020-8918

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'.

• CVE ID
• CVE-2020-8918

• Assigner
• cve-coordination@google.com

• Vulnerability Status
• Analyzed

• Published Version
• 2020-08-11T19:15:17

• Last Modified Date
• 2020-08-18T13:32:39

• Version
• 2.0

• Vector String
• AV:L/AC:L/Au:N/C:P/I:P/A:N

• Access Vector
• LOCAL

• Access Compatibility
• LOW

• Authentication
• NONE

• Confidentiality Impact
• PARTIAL

• Integrity Impact
• PARTIAL

• Availability Impact
• NONE

• Base Score
• 3.6

• Severity
• LOW

• Exploitability Score
• 3.9

• Impact Score
• 4.9

• Version
• 3.1

• Vector String
• CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

• Attack Vector
• LOCAL

• Attack Compatibility
• LOW

• Privileges Required
• LOW

• User Interaction
• NONE

• Scope
• UNCHANGED

• Confidentiality Impact
• HIGH

• Availability Impact
• NONE

• Base Score
• 7.1

• Base Severity
• HIGH

• Exploitability Score
• 1.8

• Impact Score
• 5.2