CVE-2022-3500

Workarounds

This patch can be retroactively applied to any running keylime deployment.
Only running verifiers need to be patched.
After the patch is applied, the keylime verifier needs to be restarted.

References

The problem, as well as the proposed fix, are described in detail here.
Further details about the system where the bug was found, and the conditions in which the bug was found, are available from @galmasi on demand.

For more information

If you have any questions or comments about this advisory, please comment at the bottom of the advisory itself.

This vulnerability creates a false sense of security for keylime users -- i.e. a user could query keylime and conclude that a parcitular node/agent is correctly attested, while attestations are not in fact taking place.

Short explanation: the keylime verifier creates periodic reports on the state of each attested agent. The keylime verifier runs a set of python asynchronous processes to challenge attested nodes and create reports on the outcome.

The vulnerability consists of the above named python asynchronous processes failing silently, i.e. quitting without leaving behind a database entry, raising an error or producing even a mention of an error in a log. The silent failure can be triggered by a small set of transient network failure conditions; recoverable device driver crashes being one such condition we saw in the wild.

CVE-2022-3500 has a CVSS score of 5.1 (High). The vector is requires local access, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (6.5.1); upgrading removes the vulnerable code path.

Kodem intelligence

The problem is fixed in keylime starting with tag 6.5.1

1. What is CVE-2022-3500? CVE-2022-3500 is a high-severity security vulnerability in Keylime (pip), affecting versions < 6.5.1. It is fixed in 6.5.1.
2. How severe is CVE-2022-3500? CVE-2022-3500 has a CVSS score of 5.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of Keylime are affected by CVE-2022-3500? Keylime (pip) versions < 6.5.1 is affected.
4. Is there a fix for CVE-2022-3500? Yes. CVE-2022-3500 is fixed in 6.5.1. Upgrade to this version or later.
5. Is CVE-2022-3500 exploitable, and should I be worried? Whether CVE-2022-3500 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2022-3500 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2022-3500? Upgrade Keylime to 6.5.1 or later.