CVE Vulnerabilities

CVE-2024-43803

Exposure of Sensitive Information to an Unauthorized Actor

Published: Sep 03, 2024 | Modified: Sep 03, 2024
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
4.9 MODERATE
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
Ubuntu

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 BareMetalHosts 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.

Weakness

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Affected Software

Name Vendor Start Version End Version
Red Hat OpenShift Container Platform 4.16 RedHat openshift4/ose-baremetal-rhel9-operator:v4.16.0-202409121637.p0.gae55a70.assembly.stream.el9 *

Extended Description

There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:

Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:

Information exposures can occur in different ways:

It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.

Potential Mitigations

  • Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
  • Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References