CVE-2023-32191

rke's credentials are stored in the RKE1 Cluster state ConfigMap

When RKE provisions a cluster, it stores the cluster state in a configmap called full-cluster-state inside the kube-system namespace of the cluster itself. This cluster state object contains information used to set up the K8s cluster, which may include the following sensitive data:

• RancherKubernetesEngineConfig
  • RKENodeConfig
    • SSH username
    • SSH private key
    • SSH private key path
  • RKEConfigServices
    • ETCDService
      • External client key
      • BackupConfig
        • S3BackupConfig
          • AWS access key
          • AWS secret key
    • KubeAPIService
      • SecretsEncryptionConfig
        • K8s encryption configuration (contains encryption keys)
  • PrivateRegistries
    • User
    • Password
    • ECRCredentialPlugin
      • AWS access key
      • AWS secret key
      • AWS session token
  • CloudProvider
    • AzureCloudProvider
      • AAD client ID
      • AAD client secret
      • AAD client cert password
    • OpenstackCloudProvider
      • Username
      • User ID
      • Password
    • VsphereCloudProvider
      • GlobalVsphereOpts
        • User
        • Password
      • VirtualCenterConfig
        • User
        • Password
    • HarvesterCloudProvider
      • CloudConfig
    • CustomCloudProvider
  • BastionHost
    • User
    • SSH key
• CertificatesBundle
  • Private key
• EncryptionConfig
  • Private key

The State type that contains the above info and more can viewed here.

While the full-cluster-state configmap is not publicly available (reading it requires access to the RKE cluster), it being a configmap makes it available to non-administrators of the cluster. Because this configmap contains essentially all the information and credentials required to administer the cluster, anyone with permission to read it thereby achieves admin-level access to the cluster (please consult the MITRE ATT&CK - Technique - Unsecured Credentials : Credentials In Files for further information about the associated technique of attack).

Important:
For the exposure of credentials not related to Rancher and RKE, the final impact severity for confidentiality, integrity and availability is dependent on the permissions the leaked credentials have on their services.

It is recommended to review for potentially leaked credentials in this scenario and to change them if deemed necessary.

CVE-2023-32191 has a CVSS score of 9.9 (Critical). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.4.19, 1.5.10); upgrading removes the vulnerable code path.

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This vulnerability is being fixed in RKE versions 1.4.19 and 1.5.10 which are included in Rancher versions 2.7.14 and 2.8.5.

The patches include changes that will cause RKE to automatically migrate the cluster state configmap to a full-cluster-state secret in the kube-system namespace. The migrated secret will only be accessible to those who have read access to the kube-system namespace in the downstream RKE cluster. In Rancher, only admin and cluster-owner roles can access the secret. The old configmap will be removed after successful migration.

All downstream clusters provisioned using RKE via Rancher will be migrated automatically on Rancher upgrade. Note that any downstream clusters that are unavailable or otherwise non migratable on Rancher upgrade will still be migrated automatically as soon as they become available.

Clusters provisioned using RKE outside of Rancher will be migrated automatically upon the next invocation of rke up (i.e. the next cluster reconciliation) after upgrading RKE.

If a rollback needs to be performed after an upgrade to a patched Rancher or RKE version, downstream RKE clusters that were migrated need to have their migrations manually reversed using this script: https://github.com/rancherlabs/support-tools/tree/master/reverse-rke-state-migrations.
Please be sure to back up downstream clusters before performing the reverse migration.

1. What is CVE-2023-32191? CVE-2023-32191 is a critical-severity security vulnerability in github.com/rancher/rke (go), affecting versions >= 1.4.18, < 1.4.19. It is fixed in 1.4.19, 1.5.10.
2. How severe is CVE-2023-32191? CVE-2023-32191 has a CVSS score of 9.9 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/rancher/rke are affected by CVE-2023-32191? github.com/rancher/rke (go) versions >= 1.4.18, < 1.4.19 is affected.
4. Is there a fix for CVE-2023-32191? Yes. CVE-2023-32191 is fixed in 1.4.19, 1.5.10. Upgrade to this version or later.
5. Is CVE-2023-32191 exploitable, and should I be worried? Whether CVE-2023-32191 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2023-32191 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2023-32191?
   • Upgrade github.com/rancher/rke to 1.4.19 or later
   • Upgrade github.com/rancher/rke to 1.5.10 or later