CVE-2020-8918

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

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'.

Category

6.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.02%
Third-Party Advisory github.com
Affected: Google LLC google/go-tpm library
Published at:
Updated at:

References

Link Tags
https://github.com/google/go-tpm/security/advisories/GHSA-5x29-3hr9-6wpw third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2020-8918?
CVE-2020-8918 has been scored as a medium severity vulnerability.
How to fix CVE-2020-8918?
To fix CVE-2020-8918, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2020-8918 being actively exploited in the wild?
It is possible that CVE-2020-8918 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-8918?
CVE-2020-8918 affects Google LLC google/go-tpm library.
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