A security issue was discovered in the Kubernetes Image Builder versions <= v0.1.37 where default credentials are enabled during the image build process. Virtual machine images built using the Proxmox provider do not disable these default credentials, and nodes using the resulting images may be accessible via these default credentials. The credentials can be used to gain root access. Kubernetes clusters are only affected if their nodes use VM images created via the Image Builder project with its Proxmox provider.

This vulnerability enables ssh access to minikube container using a default password.

Improper input validation in the Kubernetes API server in versions v1.0-1.12 and versions prior to v1.13.12, v1.14.8, v1.15.5, and v1.16.2 allows authorized users to send malicious YAML or JSON payloads, causing the API server to consume excessive CPU or memory, potentially crashing and becoming unavailable. Prior to v1.14.0, default RBAC policy authorized anonymous users to submit requests that could trigger this vulnerability. Clusters upgraded from a version prior to v1.14.0 keep the more permissive policy by default for backwards compatibility.

The kubectl cp command allows copying files between containers and the user machine. To copy files from a container, Kubernetes creates a tar inside the container, copies it over the network, and kubectl unpacks it on the user’s machine. If the tar binary in the container is malicious, it could run any code and output unexpected, malicious results. An attacker could use this to write files to any path on the user’s machine when kubectl cp is called, limited only by the system permissions of the local user. The untar function can both create and follow symbolic links. The issue is resolved in kubectl v1.11.9, v1.12.7, v1.13.5, and v1.14.0.

A security issue was discovered in Kubernetes where a large number of container checkpoint requests made to the unauthenticated kubelet read-only HTTP endpoint may cause a Node Denial of Service by filling the Node's disk.

The Kubernetes kubelet component allows arbitrary command execution via specially crafted gitRepo volumes.This issue affects kubelet: through 1.28.11, from 1.29.0 through 1.29.6, from 1.30.0 through 1.30.2.

A security issue was discovered in the Kubernetes Image Builder versions <= v0.1.37 where default credentials are enabled during the image build process when using the Nutanix, OVA, QEMU or raw providers. The credentials can be used to gain root access. The credentials are disabled at the conclusion of the image build process. Kubernetes clusters are only affected if their nodes use VM images created via the Image Builder project. Because these images were vulnerable during the image build process, they are affected only if an attacker was able to reach the VM where the image build was happening and used the vulnerability to modify the image at the time the image build was occurring.

A security issue was discovered in ingress-nginx where an actor with permission to create Ingress objects (in the `networking.k8s.io` or `extensions` API group) can bypass annotation validation to inject arbitrary commands and obtain the credentials of the ingress-nginx controller. In the default configuration, that credential has access to all secrets in the cluster.

A security issue was discovered in Kubernetes clusters with Windows nodes where BUILTIN\Users may be able to read container logs and NT AUTHORITY\Authenticated Users may be able to modify container logs.

A flaw was found in cri-o. A malicious container can create a symbolic link to arbitrary files on the host via directory traversal (“../“). This flaw allows the container to read and write to arbitrary files on the host system.