CVE-2022-23635 Unauthenticated control plane denial of service attack in Istio
Unauthenticated attackers can crash the Istio control plane by sending specially crafted messages to an exposed TLS port, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-23635?
CVE-2022-23635 is a high-severity denial of service vulnerability in istio, published on 22 Feb 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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. 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](https://istio.io/latest/docs/setup/install/multicluster/primary-remote/) topologies, this port is exposed over the public internet. 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.
Which versions are affected by CVE-2022-23635?
6 open source packages ship an affected version, including istio.io/istio. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
istio.io/istio Go | All versions | 1.11.7 |
istio.io/istio Go | All versions | 1.11.7 |
istio.io/istio Go | From 1.12.0 | 1.12.4 |
istio.io/istio Go | From 1.12.0 | 1.12.4 |
istio.io/istio Go | From 1.13.0 | 1.13.1 |
istio.io/istio Go | From 1.13.0 | 1.13.1 |
Products include Istio Istio.
How do I fix CVE-2022-23635?
Upgrade istio.io/istio to a fixed version for your release line: 1.11.7, 1.12.4 or 1.13.1.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-23635 being exploited?
There is no known exploitation of CVE-2022-23635 in the wild and no public exploit code.
Other vulnerabilities in istio
- CVE-2021-31921 Missing authorization in n/a
- CVE-2021-34824 Information disclosure in n/a
- CVE-2026-31837 Istio JWKS resolver to prevent private key material from being exposed when JWKS fetch fails.
- CVE-2021-39155 Authorization Policy Bypass Due to Case Insensitive Host Comparison
- CVE-2021-39156 Fragments in Path May Lead to Authorization Policy Bypass
Sources
Also known as GHSA-856q-xv3c-7f2f, MINI-5mw8-jwcq-jjmj, MINI-9gfr-m7j2-fqqf.