Authorization Bypass Through User-Controlled Key Affecting keylime package, versions [,7.5.0)


Severity

Recommended
0.0
medium
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.06% (27th percentile)

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  • Snyk IDSNYK-PYTHON-KEYLIME-5862621
  • published27 Aug 2023
  • disclosed23 Aug 2023
  • creditFlorian Kohnhäuser

Introduced: 23 Aug 2023

CVE-2023-38201  (opens in a new tab)
CWE-639  (opens in a new tab)

How to fix?

Upgrade keylime to version 7.5.0 or higher.

Overview

keylime is a TPM-based key bootstrapping and system integrity measurement system for cloud

Affected versions of this package are vulnerable to Authorization Bypass Through User-Controlled Key via the registrar code, which allows an attacker to effectively bypass the challenge-response protocol used to verify that an agent has indeed access to an AIK, which in indeed related to the EK. When receiving the wrong auth_tag back from the agent during activation, the registrar answers with an error message containing the expected correct auth_tag (an HMAC calculated within the registrar for checking), which the attacker then uses.

References

CVSS Scores

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