CVE-2022-24726 Explained : Impact and Mitigation

Istio is an open platform to connect, manage, and secure microservices. An unauthenticated control plane denial of service attack vulnerability has been identified in Istio versions < 1.11.8, >= 1.12.0, < 1.12.5, and >= 1.13.0, < 1.13.2. Attackers can exploit this vulnerability by sending a specially crafted message to the Istio control plane component, istiod, causing it to crash. The vulnerability lies in the validating webhook when exposed publicly over TLS port 15017 without requiring authentication. For some deployments, especially external Istio topologies, this port may be exposed over the public internet, increasing the risk. A patch has been released in versions 1.13.2, 1.12.5, and 1.11.8, and users are strongly advised to upgrade. If upgrading is not immediately possible, users should restrict access to the validating webhook or limit querying IP addresses to trusted entities.

Understanding CVE-2022-24726

This section delves into the details of the Istio unauthenticated control plane denial of service attack vulnerability.

What is CVE-2022-24726?

CVE-2022-24726 is a vulnerability in Istio that allows unauthenticated attackers to carry out denial of service attacks on the Istio control plane.

The Impact of CVE-2022-24726

The vulnerability poses a high risk to Istio deployments, especially when the Istio control plane is publicly exposed, potentially leading to service disruption and crashes.

Technical Details of CVE-2022-24726

This section covers the technical aspects of the CVE-2022-24726 vulnerability.

Vulnerability Description

The vulnerability arises from a request processing error in the Istio control plane component, istiod, allowing attackers to crash the control plane.

Affected Systems and Versions

Istio versions < 1.11.8, >= 1.12.0, < 1.12.5, and >= 1.13.0, < 1.13.2 are impacted by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by sending a specially crafted message to the validating webhook, crashing the istiod component.

Mitigation and Prevention

Learn how to secure your Istio deployment against CVE-2022-24726.

Immediate Steps to Take

Users are urged to upgrade to patched versions 1.13.2, 1.12.5, or 1.11.8 as soon as possible. If upgrading is not feasible, restrict public access to the validating webhook.

Long-Term Security Practices

Establish long-term security measures to protect Istio deployments, such as regular security updates and monitoring.

Patching and Updates

Stay informed about security patches and updates from Istio to mitigate known vulnerabilities.