CVE-2023-34242

Workarounds

There is no workaround to this issue.

Acknowledgements

The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @meyskens for investigating and fixing the issue.

For more information

If you have any questions or comments about this advisory, please reach out on Slack.

As usual, if you think you found a related vulnerability, we strongly encourage you to report security vulnerabilities to our private security mailing list: [email protected] - first, before disclosing them in any public forums. This is a private mailing list where only members of the Cilium internal security team are subscribed to, and is treated as top priority.

When the Gateway API is enabled in Cilium, the absence of a check on the namespace in which a ReferenceGrant is created could result in Cilium gaining visibility of secrets (including certificates) and services across namespaces.

An attacker on an affected cluster can configure Cilium to use cluster secrets or communicate with services that it should not have access to.

Gateway API functionality is disabled by default.

CVE-2023-34242 has a CVSS score of 3.4 (Low). The vector is reachable from an adjacent network, high 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 (1.13.4); upgrading removes the vulnerable code path.

Kodem intelligence

This vulnerability is fixed in Cilium release 1.13.4.

Cilium versions <1.13 are not affected.

1. What is CVE-2023-34242? CVE-2023-34242 is a low-severity security vulnerability in github.com/cilium/cilium (go), affecting versions >= 1.13.0, < 1.13.4. It is fixed in 1.13.4.
2. How severe is CVE-2023-34242? CVE-2023-34242 has a CVSS score of 3.4 (Low). 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 github.com/cilium/cilium are affected by CVE-2023-34242? github.com/cilium/cilium (go) versions >= 1.13.0, < 1.13.4 is affected.
4. Is there a fix for CVE-2023-34242? Yes. CVE-2023-34242 is fixed in 1.13.4. Upgrade to this version or later.
5. Is CVE-2023-34242 exploitable, and should I be worried? Whether CVE-2023-34242 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-2023-34242 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-2023-34242? Upgrade github.com/cilium/cilium to 1.13.4 or later.