[ANNOUNCE] Security regression in Kubernetes kubelet v1.13.6 and v1.14.2 only - CVE-2019-11245

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Brandon Philips

May 30, 2019, 5:57:39 PM5/30/19
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Hello Kubernetes Community-

A security-related issue was discovered in kubelet versions v1.13.6 and v1.14.2. The issue is medium severity and can be mitigated with a pod spec configuration change OR by **downgrading** kubelets to v1.13.5 or v1.14.1.

**Vulnerability Details**

When a container runs for the first time on a node, it correctly respects the UID set by the container image (e.g. USER in a Dockerfile). However, on the second run, the container will run as UID 0 (aka root) which can be an undesired escalated privilege.

Pods that specify an explicit runAsUser are unaffected and continue to work properly.

PodSecurityPolicies that force a runAsUser setting are also unaffected and continue to work properly.

Pods that specify mustRunAsNonRoot:true will refuse to start the container as uid 0, which can affect availability.

This issue is filed as CVE-2019-11245. See https://github.com/kubernetes/kubernetes/issues/78308 for more details.

**Am I vulnerable?**

Run this to print out all nodes and their kubelet version:

kubectl get nodes -o=jsonpath='{range .items[*]}{.status.nodeInfo.machineID}{"\t"}{.status.nodeInfo.kubeletVersion}{"\n"}{end}'

If the output lists Kubelet versions listed below you are running a vulnerable version:

  • v1.13.6

  • v1.14.2

**How do I mitigate the vulnerability?**

There are two potential mitigations to this issue:

**How do I upgrade?**

An upgrade addressing this issue is not yet available. But, will appear in v1.13.7 and v1.14.3 ASAP and will be announced here.

**Thank you**

Thank you to the many reporters, and Tim Pepper as release manager for the coordination in making this announcement.

Thank You,

Brandon on behalf of the Kubernetes Product Security Committee

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