CVE-2022-23635

Workarounds

There are no effective workarounds, beyond upgrading. Limiting network access to Istiod to the minimal set of clients can help lessen the scope of the vulnerability to some extent.

References

More details can be found in the Istio Security Bulletin

For more information

If you have any questions or comments about this advisory, please email us at [email protected]

The Istio control plane, istiod, is vulnerable to a request processing error, allowing a malicious attacker that sends a specially crafted message which results in the control plane crashing. This endpoint is served over TLS port 15012, but does not require any authentication from the attacker.

For simple installations, Istiod is typically only reachable from within the cluster, limiting the blast radius. However, for some deployments, especially multicluster topologies, this port is exposed over the public internet.

The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.

CVE-2022-23635 has a CVSS score of 7.5 (High). The vector is network-reachable, 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 (1.13.1, 1.12.4, 1.11.7); upgrading removes the vulnerable code path.

Kodem intelligence

• Istio 1.13.1 and above
• Istio 1.12.4 and above
• Istio 1.11.7 and above

1. What is CVE-2022-23635? CVE-2022-23635 is a high-severity improper authentication vulnerability in istio.io/istio (go), affecting versions = 1.13.0. It is fixed in 1.13.1, 1.12.4, 1.11.7. The application does not adequately verify the identity of a user, device, or process before granting access.
2. How severe is CVE-2022-23635? CVE-2022-23635 has a CVSS score of 7.5 (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 istio.io/istio are affected by CVE-2022-23635? istio.io/istio (go) versions = 1.13.0 is affected.
4. Is there a fix for CVE-2022-23635? Yes. CVE-2022-23635 is fixed in 1.13.1, 1.12.4, 1.11.7. Upgrade to this version or later.
5. Is CVE-2022-23635 exploitable, and should I be worried? Whether CVE-2022-23635 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-2022-23635 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-2022-23635?
   • Upgrade istio.io/istio to 1.13.1 or later
   • Upgrade istio.io/istio to 1.12.4 or later
   • Upgrade istio.io/istio to 1.11.7 or later