Rancher Fleet Helm Values are stored inside BundleDeployment in plain text

Impact

A vulnerability has been identified when using Fleet to manage Helm charts where sensitive information is passed through BundleDeployment.Spec.Options.Helm.Values may be stored in plain text. This can result in:

1. Unauthorized disclosure of sensitive data: Any user with GET or LIST permissions on BundleDeployment resources could retrieve Helm values containing credentials or other secrets.
2. Lack of encryption at rest: BundleDeployment is not configured for Kubernetes encryption at rest by default, causing sensitive values to remain unencrypted within the cluster datastore.

This behavior differs from Helm v3’s default approach, where chart state — including values — is stored in Kubernetes secrets, benefiting from built-in protection mechanisms. In affected scenarios, credentials and other sensitive information are exposed both at rest and in responses to API calls.

Please consult the associated MITRE ATT&CK - Technique - Credentials from Password Stores for further information about this category of attack.

For the exposure of credentials not related to Rancher, the final impact severity for confidentiality, integrity, and availability is dependent on the permissions that the leaked credentials have on their own services. It is recommended to review the potentially exposed sensitive data in this scenario and change secrets, tokens, and passwords as necessary.

Patches

This vulnerability is addressed by adding the capability for each Bundle and BundleDeployment to have a secret to store options in.

1. The git job that runs fleet apply will now create secrets for Helm values.
2. Fleet controller generates bundledeployments and now creates a Helm values secret per bundle deployment in the cluster namespace.
3. Fleet agent uses the bundledeployment for options, the content resource and the secret to deploy the bundle.

Patched versions of Fleet include releases v0.14.0, v0.13.1, v0.12.6 and v0.11.10.

Workarounds

If you can't upgrade to a fixed version, please make sure to specify paths to valuesFiles as simple file names, e.g.:

Instead of:

helm:
  valuesFiles:
    - config-chart/values.yaml # will not be excluded → risky

Use:

helm:
  valuesFiles:
    - values.yaml # will be excluded

References

If you have any questions or comments about this advisory:

• Reach out to the SUSE Rancher Security team for security related inquiries.
• Open an issue in the Rancher repository.
• Verify with our support matrix and product support lifecycle.