Charmed Kubernetes update for upstream API server vulnerability

Canonical

on August 5, 2019

An upstream Kubernetes vulnerability (CVE-2019-11247) has been identified where the API server mistakenly allows access to a cluster-scoped custom resource, if the request is made as if the resource were namespaced. Authorisations for the resource accessed in this manner are enforced using roles and role bindings within the namespace. This means that a user with access only to a resource in one namespace could create, view updates or delete the cluster-scoped resource (according to their namespace role privileges). 

Charmed Kubernetes has already been patched to mitigate against this vulnerability. Patched builds of the 1.13.8, 1.14.4 and 1.15.1 kube-apiserver snap have also been published.

The vulnerability, of medium severity, has also been patched in the following upstream version of Kubernetes – 1.13.9, 1.14.5 and 1.15.2. Users are encouraged to update to one of these versions now. 

To mitigate against the vulnerability in an unpatched version, users should remove authorisation rules that grant access to cluster-scoped resources within namespaces. For example, RBAC roles and clusterroles intended to be referenced by rolebindings should not grant access to `resources:[*], apiGroups:[*]`, or grant access to cluster-scoped custom resources.

More information can be found on the Knowledge Base.

Newsletter signup

Select topics you’re
interested in

In submitting this form, I confirm that I have read and agree to Canonical’s Privacy Notice and Privacy Policy.

Related posts

We are changing the way you build snaps from GitHub repos

On the 11th March 2020 we introduced a new process for building a snap using GitHub repos to snapcraft.io. Here is all you need to know about this update....

GNOME 3.34 snapcraft extension

We constantly strive to empower developers. Part of that aim extends to making development easier, for example improving build tools and documentation. As an...

An adventure through the Snap Store

An application store with a large number of entries is a double-edged sword. It’s often a good sign of a vibrant, thriving community of software creators,...