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.

The remote Oracle Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2019-4593 advisory.

  - Cloud Native Computing Foundation (CNCF) CNI (Container Networking Interface) 0.7.4 has a network firewall     misconfiguration which affects Kubernetes. The CNI 'portmap' plugin, used to setup HostPorts for CNI,     inserts rules at the front of the iptables nat chains; which take precedence over the KUBE- SERVICES     chain. Because of this, the HostPort/portmap rule could match incoming traffic even if there were better     fitting, more specific service definition rules like NodePorts later in the chain. The issue is fixed in     CNI 0.7.5 and Kubernetes 1.11.9, 1.12.7, 1.13.5, and 1.14.0. (CVE-2019-9946)

  - 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. (CVE-2019-1002101)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

An update of the kubernetes package has been released.

The version of Kubernetes installed on the remote host is version 1.11.x prior to 1.11.9, 1.12.x prior to 1.12.7 or 1.13.x prior to 1.13.5. It is, therefore, affected by a directory traversal vulnerability in the kubectl cp command due to mishandling of symlinks when copying files from a running container. An unauthenticated, remote attacker can exploit this, by convincing a user to use kubectl cp with a malicious container to overwrite arbitrary files on the remote host.

Update to v1.15.2 + carry upstream #81330

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Kubernetes.io reports :

A security issue was discovered with the Kubernetes kubectl cp command that could enable a directory traversal replacing or deleting files on a user's workstation.

ID	Name	Product	Family	Severity
180683	Oracle Linux 7 : kubernetes / kubeadm-upgrade / kubeadm-ha-setup (ELSA-2019-4593)	Nessus	Oracle Linux Local Security Checks	high
140706	Photon OS 3.0: Kubernetes PHSA-2020-3.0-0142	Nessus	PhotonOS Local Security Checks	medium
128650	Kubernetes 1.11.x < 1.11.9 / 1.12.x < 1.12.7 / 1.13.x < 1.13.5 kubectl directory traversal	Nessus	Misc.	medium
128127	Fedora 30 : kubernetes (2019-2b8ef08c95)	Nessus	Fedora Local Security Checks	high
123574	FreeBSD : Kubectl -- Potential directory traversal (6a0129bf-54ad-11e9-987c-1c39475b9f84)	Nessus	FreeBSD Local Security Checks	medium

Detections

Analytics

CVE-2019-1002101

medium

Tenable Plugins

high

medium

medium

high

medium