CVE-2024-43803
Vulnérabilité moyenne dans baremetal-operator (metal3-io)
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 other than cluster administrators to have RBAC access to create/edit a `BareMetalHost`. This vulnerability is only meaningful, if the cluster has users other than administrators and users' privileges are limited to their respective namespaces. The patch prevents BMO from accepting links to Secrets from other namespaces as BMH input. Any BMH configuration is only read from the same namespace only. The problem is patched in BMO releases v0.7.0, v0.6.2 and v0.5.2 and users should upgrade to those versions. Prior upgrading, duplicate the BMC Secrets to the namespace where the corresponding BMH is. After upgrade, remove the old Secrets. As a workaround, an operator can configure BMO RBAC to be namespace scoped for Secrets, instead of cluster scoped, to prevent BMO from accessing Secrets from other namespaces.
Gravité et risque d'exploitation
CVE-2024-43803 obtient un score CVSS de 4.9/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.57 %, ce qui la place devant 46.3 % des CVE référencées.
Que faire ?
- Vérifiez si baremetal-operator (versions >= 0.6.0, < 0.6.2, >= 0.7.0, < 0.8.0, < 0.5.2) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://github.com/metal3-io/baremetal-operator/security/advisories/GHSA-pqfh-xh7w-7h3p
- https://github.com/metal3-io/baremetal-operator/pull/1929
- https://github.com/metal3-io/baremetal-operator/pull/1930
- https://github.com/metal3-io/baremetal-operator/pull/1931
- https://github.com/metal3-io/baremetal-operator/commit/3af4882e9c5fadc1a7550f53daea21dccd271f74
- https://github.com/metal3-io/baremetal-operator/commit/bedae7b997d16f36e772806681569bb8eb4dadbb
- https://github.com/metal3-io/baremetal-operator/commit/c2b5a557641bc273367635124047d6c958aa15f7
