CVE-2023-26484: On a compromised KubeVirt node, the virt-handler service account can be used to modify all node specs

Vulnerability summary

CVE-2023-26484 is a high (CVSS 8.2) Incorrect Authorization vulnerability in kubevirt. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 49.3% of scored vulnerabilities.

Timeline

1. 15-03-2023
   PublishedVulnerability first disclosed.
2. 25-02-2025
   Last modifiedVulnerability information updated.

Description

KubeVirt is a virtual machine management add-on for Kubernetes. In versions 0.59.0 and prior, if a malicious user has taken over a Kubernetes node where virt-handler (the KubeVirt node-daemon) is running, the virt-handler service account can be used to modify all node specs. This can be misused to lure-in system-level-privileged components which can, for instance, read all secrets on the cluster, or can exec into pods on other nodes. This way, a compromised node can be used to elevate privileges beyond the node until potentially having full privileged access to the whole cluster. The simplest way to exploit this, once a user could compromise a specific node, is to set with the virt-handler service account all other nodes to unschedulable and simply wait until system-critical components with high privileges appear on its node. No patches are available as of time of publication. As a workaround, gatekeeper users can add a webhook which will block the `virt-handler` service account to modify the spec of a node.

• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.