KubeVirt is a virtual machine management add-on for Kubernetes. The `hostDisk` feature in KubeVirt allows mounting a host file or directory owned by the user with UID 107 into a VM. However, prior to version 1.6.1 and 1.7.0, the implementation of this feature and more specifically the `DiskOrCreate` option (which creates a file if it doesn't exist) has a logic bug that allows an attacker to read and write arbitrary files owned by more privileged users on the host system. Versions 1.6.1 and 1.7.0 fix the issue.

Affected: Go: kubevirt.io/kubevirt

### Summary The `hostDisk` feature in KubeVirt allows mounting a host file or directory owned by the user with UID 107 into a VM. However, the implementation of this feature and more specifically the `DiskOrCreate` option which creates a file if it doesn't exist, has a logic bug that allows an attacker to read and write arbitrary files owned by more privileged users on the host system.

### Details The `hostDisk` feature gate in KubeVirt allows mounting a QEMU RAW image directly from the host into a VM. While similar features, such as mounting disk images from a PVC, enforce ownership-based restrictions (e.g., only allowing files owned by specific UID, this mechanism can be subverted. For a RAW disk image to be readable by the QEMU process running within the `virt-launcher` pod, it must be owned by a user with UID 107. **If this ownership check is considered a security barrier, it can be bypassed**. In addition, the ownership of the host files mounted via this feature is changed to the user with UID 107.

The above is due to a logic bug in the code of the `virt-handler` component which prepares and sets the permissions of the volumes and data inside which are going to be mounted in the `virt-launcher` pod and consecutively consumed by the VM. It is triggered when one tries to mount a host file or directory using the `DiskOrCreate` option. The relevant code is as follows:

```go // pkg/host-disk/host-disk.go

func (hdc DiskImgCreator) Create(vmi *v1.VirtualMachineInstance)…

Security update for kubevirt

Security update for kubevirt