GitHub Advisoryadvisory · Go
GHSA-pqfh-xh7w-7h3p The Bare Metal Operator (BMO) can expose particularly named secrets from other namespaces via BMH CRD
MEDIUM
Official page ↗
- Aliases
- CVE-2024-43803
- Ecosystem
- Go
- Packages
- github.com/metal3-io/baremetal-operator
- Severity
- Moderate
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
- Weaknesses
- CWE-200, CWE-653
- Reviewed
- 2024-09-03
Affected packages
• Go github.com/metal3-io/baremetal-operator: >= 0.7.0-rc.0, < 0.8.0 → fixed in 0.8.0
• Go github.com/metal3-io/baremetal-operator: >= 0.6.0, < 0.6.2 → fixed in 0.6.2
• Go github.com/metal3-io/baremetal-operator: < 0.5.2 → fixed in 0.5.2
Description
Impact
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 the baremetal-operator 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).
Limiting factors
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.
Patches
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 v0.8.0, v0.6.2 and v0.5.2 and users should upgrade to those versions. Prior upgrading and if needed, duplicate the BMC Secrets to the namespace where the corresponding BMH is. After upgrade, remove the old Secrets.
Workarounds
Operator can configure BMO RBAC to be namespace scoped for Secrets, instead of cluster scoped, to prevent BMO from accessing Secrets from other namespaces.
References
• https://nvd.nist.gov/vuln/detail/CVE-2024-43803
• 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
Related
Alias · CVE (1)
- CVE-2024-43803 The Bare Metal Operator (BMO) implements a Kubernetes API for managing bare metal hosts in Metal3. vulnerability
References
- https://github.com/metal3-io/baremetal-operator/security/advisories/GHSA-pqfh-xh7w-7h3p web
- https://nvd.nist.gov/vuln/detail/CVE-2024-43803 advisory
- https://github.com/metal3-io/baremetal-operator/pull/1929 web
- https://github.com/metal3-io/baremetal-operator/pull/1930 web
- https://github.com/metal3-io/baremetal-operator/pull/1931 web
- https://github.com/metal3-io/baremetal-operator/commit/3af4882e9c5fadc1a7550f53daea21dccd271f74 web
- https://github.com/metal3-io/baremetal-operator/commit/bedae7b997d16f36e772806681569bb8eb4dadbb web
- https://github.com/metal3-io/baremetal-operator/commit/c2b5a557641bc273367635124047d6c958aa15f7 web
- https://github.com/metal3-io/baremetal-operator package