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.

A flaw was found in the KubeVirt main virt-handler versions before 0.26.0 regarding the access permissions of virt-handler. An attacker with access to create VMs could attach any secret within their namespace, allowing them to read the contents of that secret.

A flaw was found in kubevirt 0.29 and earlier. Virtual Machine Instances (VMIs) can be used to gain access to the host's filesystem. Successful exploitation allows an attacker to assume the privileges of the VM process on the host system. In worst-case scenarios an attacker can read and modify any file on the system where the VMI is running. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.