CVE-2022-23635: istio Improper Authentication

Vulnerability summary

CVE-2022-23635 is a high (CVSS 7.5) Improper Authentication vulnerability in istio. EPSS estimates a 1.66% chance of exploitation in the next 30 days, higher than 76.3% of scored vulnerabilities.

Timeline

1. 22-02-2022
   PublishedVulnerability first disclosed.
2. 23-04-2025
   Last modifiedVulnerability information updated.

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.

• CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
• CWE-1284Improper Validation of Specified Quantity in InputThe product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.