[Security Advisory] CVE-2022-3162: Unauthorized read of Custom Resources
Tim Allclair
Hello Kubernetes Community,
A security issue was discovered in Kubernetes where users authorized to list or watch one type of namespaced custom resource cluster-wide can read custom resources of a different type in the same API group without authorization.
This issue has been rated Medium (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N), and assigned CVE-2022-3162
Am I vulnerable?
Clusters are impacted by this vulnerability if all of the following are true:
There are 2+ CustomResourceDefinitions sharing the same API group
Users have cluster-wide list or watch authorization on one of those custom resources.
The same users are not authorized to read another custom resource in the same API group.
Affected Versions
Kubernetes kube-apiserver <= v1.25.3
Kubernetes kube-apiserver <= v1.24.7
Kubernetes kube-apiserver <= v1.23.13
Kubernetes kube-apiserver <= v1.22.15
How do I mitigate this vulnerability?
Upgrading the kube-apiserver to a fixed version mitigates this vulnerability.
Prior to upgrading, this vulnerability can be mitigated by avoiding granting cluster-wide list and watch permissions.
Fixed Versions
Kubernetes kube-apiserver v1.25.4
Kubernetes kube-apiserver v1.24.8
Kubernetes kube-apiserver v1.23.14
Kubernetes kube-apiserver v1.22.16
These releases will be published over the course of today, November 10th.
Detection
Requests containing `..` in the request path are a likely indicator of exploitation. Request paths may be captured in API audit logs, or in kube-apiserver HTTP logs.
If you find evidence that this vulnerability has been exploited, please contact secu...@kubernetes.io
Additional Details
See the GitHub issue for more details: https://github.com/kubernetes/kubernetes/issues/113756
Acknowledgements
This vulnerability was reported by Richard Turnbull of NCC Group as part of the Kubernetes Audit.
Thank You,
Tim Allclair on behalf of the Kubernetes Security Response Committee