Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. Versions prior to 3.31.0 ship with a default configuration that allows pod creators to inject arbitrary command-line arguments into the virtiofsd process through the `io.katacontainers.config.hypervisor.virtio_fs_extra_args` pod annotation. By injecting `-o source=/` along with `--no-announce-submounts` and `--sandbox=none`, an attacker can override the virtiofsd shared directory to serve the entire host root filesystem into the guest VM. Combined with the `kernel_params` annotation (also enabled by default) to activate the agent debug console, the attacker can mount the host filesystem from inside the VM and read or write any file on the host, including /etc/shadow. Version 3.31.0 patches the issue.

Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. From v3.4.0 to v3.28.0, an oversight in the CopyFile policy (and perhaps the CopyFile handler) allows untrusted hosts to write to arbitrary locations inside the guest workload image. This can be used to overwrite binaries inside the guest and exfiltrate data from containers; even those running inside CVMs. This vulnerability is fixed in v3.29.0.

Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. In versions prior to 3.27.0, an issue in Kata with Cloud Hypervisor allows a user of the container to modify the file system used by the Guest micro VM ultimately achieving arbitrary code execution as root in said VM. The current understanding is this doesn’t impact the security of the Host or of other containers / VMs running on that Host (note that arm64 QEMU lacks NVDIMM read-only support: It is believed that until the upstream QEMU gains this capability, a guest write could reach the image file). Version 3.27.0 patches the issue.

Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. In versions prior to 3.26.0, when a container image is malformed or contains no layers, containerd falls back to bind-mounting an empty snapshotter directory for the container rootfs. When the Kata runtime attempts to mount the container rootfs, the bind mount causes the rootfs to be detected as a block device, leading to the underlying device being hotplugged to the guest. This can cause filesystem-level errors on the host due to double inode allocation, and may lead to the host's block device being mounted as read-only. Version 3.26.0 contains a patch for the issue.

An issue was discovered in Kata Containers through 1.11.3 and 2.x through 2.0-rc1. The runtime will execute binaries given using annotations without any kind of validation. Someone who is granted access rights to a cluster will be able to have kata-runtime execute arbitrary binaries as root on the worker nodes.

An improper file permissions vulnerability affects Kata Containers prior to 1.11.5. When using a Kubernetes hostPath volume and mounting either a file or directory into a container as readonly, the file/directory is mounted as readOnly inside the container, but is still writable inside the guest. For a container breakout situation, a malicious guest can potentially modify or delete files/directories expected to be read-only.

A malicious guest compromised before a container creation (e.g. a malicious guest image or a guest running multiple containers) can trick the kata runtime into mounting the untrusted container filesystem on any host path, potentially allowing for code execution on the host. This issue affects: Kata Containers 1.11 versions earlier than 1.11.1; Kata Containers 1.10 versions earlier than 1.10.5; Kata Containers 1.9 and earlier versions.

Kata Containers doesn't restrict containers from accessing the guest's root filesystem device. Malicious containers can exploit this to gain code execution on the guest and masquerade as the kata-agent. This issue affects Kata Containers 1.11 versions earlier than 1.11.1; Kata Containers 1.10 versions earlier than 1.10.5; and Kata Containers 1.9 and earlier versions.

Kata Containers before 1.11.0 on Cloud Hypervisor persists guest filesystem changes to the underlying image file on the host. A malicious guest can overwrite the image file to gain control of all subsequent guest VMs. Since Kata Containers uses the same VM image file with all VMMs, this issue may also affect QEMU and Firecracker based guests.

An improper link resolution vulnerability affects Kata Containers versions prior to 1.11.0. Upon container teardown, a malicious guest can trick the kata-runtime into unmounting any mount point on the host and all mount points underneath it, potentiality resulting in a host DoS.