CVE-2024-43803

Technical Description

The Bare Metal Operator (BMO) implements a Kubernetes API for managing bare metal hosts in Metal3. The `BareMetalHost` (BMH) CRD allows the `userData`, `metaData`, and `networkData` for the provisioned host to be specified as links to Kubernetes Secrets. There are fields for both the `Name` and `Namespace` of the Secret, meaning that versions of the baremetal-operator prior to 0.8.0, 0.6.2, and 0.5.2 will read a `Secret` from any namespace. A user with access to create or edit a `BareMetalHost` can thus exfiltrate a `Secret` from another namespace by using it as e.g. the `userData` for provisioning some host (note that this need not be a real host, it could be a VM somewhere).

BMO will only read a key with the name `value` (or `userData`, `metaData`, or `networkData`), so that limits the exposure somewhat. `value` is probably a pretty common key though. Secrets used by _other_ `BareMetalHost`s in different namespaces are always vulnerable. It is probably relatively unusual for anyone

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References