Grafana Operator: Privilege escalation from namespace admin to cluster admin via GrafanaDashboard jsonnetLib fileName

We have released version 5.24.0 of the Grafana Operator. This patch includes a MODERATE severity security fix for a path traversal/privilege escalation vulnerability in the Grafana Operator.

Summary

The Grafana Operator supports loading dashboards & library panels using the jsonnet data templating language. The jsonnet expression is evaluated in the context of the operator manager pod.

Impact

It is possible for a malicious user who can create Dashboard or LibraryPanel resources for a Grafana instance to obtain the Kubernetes service account token of the Grafana Operator manager.

Affected versions

All Grafana Operator versions <= 5.23

Solutions and mitigations

All installations should be upgraded as soon as possible.

As a workaround, the following ValidatingAdmissionPolicy prevent the creation or modification of jsonnet based resources:

apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicy
metadata:
  name: "prevent-jsonnet-dashboards"
spec:
  failurePolicy: Fail
  matchConstraints:
    resourceRules:
      - apiGroups: ["grafana.integreatly.org"]
        apiVersions: ["v1beta1"]
        operations: ["CREATE", "UPDATE"]
        resources: ["grafanadashboards", "grafanalibrarypanels"]
  validations:
    - expression: "!has(object.spec.jsonnetLib)"
---
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicyBinding
metadata:
  name: "prevent-jsonnet-dashboards-clusterwide"
spec:
  policyName: "prevent-jsonnet-dashboards"
  validationActions: [Deny]

Acknowledgement

We would like to thank Artem Cherezov for responsibly disclosing the vulnerability.