Описание
The Bare Metal Operator (BMO) implements a Kubernetes API for managing bare metal hosts in Metal3. Baremetal Operator enables users to load Secret from arbitrary namespaces upon deployment of the namespace scoped Custom Resource BMCEventSubscription. Prior to versions 0.8.1 and 0.9.1, an adversary Kubernetes account with only namespace level roles (e.g. a tenant controlling a namespace) may create a BMCEventSubscription in his authorized namespace and then load Secrets from his unauthorized namespaces to his authorized namespace via the Baremetal Operator, causing Secret Leakage. The patch makes BMO refuse to read Secrets from other namespace than where the corresponding BMH resource is. The patch does not change the BMCEventSubscription API in BMO, but stricter validation will fail the request at admission time. It will also prevent the controller reading such Secrets, in case the BMCES CR has already been deployed. The issue exists for all versions of BMO, and is patched in BMO releases v0.9.1 and v0.8.1. Prior upgrading to patched BMO version, duplicate any existing Secret pointed to by BMCEventSubscription's httpHeadersRef to the same namespace where the corresponding BMH exists. After upgrade, remove the old Secrets. As a workaround, the operator can configure BMO RBAC to be namespace scoped, instead of cluster scoped, to prevent BMO from accessing Secrets from other namespaces, and/or use WATCH_NAMESPACE configuration option to limit BMO to single namespace.
A flaw was found in the Bare Metal Operator (BMO) Kubernetes API component. BMO enables users to load Secrets from arbitrary namespaces upon deployment of the namespace-scoped Custom Resource BMCEventSubscription. In affected versions, an adversary using a Kubernetes account with only namespace level roles (e.g. a tenant controlling a namespace) may create a BMCEventSubscription in their authorized namespace and then load Secrets from their unauthorized namespaces to another authorized namespace via the Baremetal Operator, which can lead to the exposure of secrets and credential information.
Отчет
This vulnerability is rated as Important for OpenShift Baremetal Operator, because RBAC is cluster-scoped and, while WATCH_NAMESPACE is set to openshift-machine-api by default, it is common for deployments to have a less restrictive value configured. It breaks Kubernetes' namespace isolation by allowing a user to create a BMCEventSubscription that references Secrets from unauthorized namespaces. In OpenShift, where Secrets often store high-value assets like kubeadmin credentials or cloud API keys, this enables unauthorized access to sensitive data across tenant boundaries. It effectively becomes a horizontal privilege escalation vector, allowing a namespace-scoped user to exfiltrate secrets intended for other components or tenants. Given the minimal exploit complexity and high-impact potential, especially in multi-tenant environments, this issue is more severe than a moderate flaw and justifies a high CVSS rating.
Меры по смягчению последствий
Operator can configure BMO role-based access control (RBAC) to be namespace scoped instead of cluster scoped to prevent BMO from accessing Secrets from other namespaces, or use the WATCH_NAMESPACE configuration option to limit BMO to a single namespace.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Assisted Installer for Red Hat OpenShift Container Platform 2 | rhai-tech-preview/assisted-installer-reporter-rhel8 | Fix deferred | ||
| Assisted Installer for Red Hat OpenShift Container Platform 2 | rhai-tech-preview/assisted-installer-rhel8 | Fix deferred | ||
| Multicluster Engine for Kubernetes | multicluster-engine/agent-service-rhel8 | Fix deferred | ||
| Multicluster Engine for Kubernetes | multicluster-engine/assisted-installer-controller-rhel8 | Fix deferred | ||
| Multicluster Engine for Kubernetes | multicluster-engine/assisted-installer-reporter-rhel8 | Fix deferred | ||
| Multicluster Engine for Kubernetes | multicluster-engine/assisted-installer-rhel8 | Fix deferred | ||
| Multicluster Engine for Kubernetes | multicluster-engine/assisted-service-8-rhel8 | Fix deferred | ||
| Multicluster Engine for Kubernetes | multicluster-engine/assisted-service-9-rhel9 | Fix deferred | ||
| Multicluster Engine for Kubernetes | multicluster-engine/hive-rhel8 | Fix deferred | ||
| Multicluster Engine for Kubernetes | multicluster-engine/image-based-install-rhel9 | Fix deferred |
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Дополнительная информация
Статус:
EPSS
8.2 High
CVSS3
Связанные уязвимости
The Bare Metal Operator (BMO) implements a Kubernetes API for managing bare metal hosts in Metal3. Baremetal Operator enables users to load Secret from arbitrary namespaces upon deployment of the namespace scoped Custom Resource `BMCEventSubscription`. Prior to versions 0.8.1 and 0.9.1, an adversary Kubernetes account with only namespace level roles (e.g. a tenant controlling a namespace) may create a `BMCEventSubscription` in his authorized namespace and then load Secrets from his unauthorized namespaces to his authorized namespace via the Baremetal Operator, causing Secret Leakage. The patch makes BMO refuse to read Secrets from other namespace than where the corresponding BMH resource is. The patch does not change the `BMCEventSubscription` API in BMO, but stricter validation will fail the request at admission time. It will also prevent the controller reading such Secrets, in case the BMCES CR has already been deployed. The issue exists for all versions of BMO, and is patched in BMO
Bare Metal Operator (BMO) can expose any secret from other namespaces via BMCEventSubscription CRD
EPSS
8.2 High
CVSS3