Red Hat Multicluster Engine For Kubernetes vulnerabilities

A flaw was found in Maestro. Its REST API write endpoints were registered without proper authentication middleware. This allows a remote attacker to perform unauthorized write operations, such as creating, modifying, or deleting consumers and resource bundles. This could lead to data integrity issues or a denial of service (DoS).

A flaw was found in maestro. A remote attacker could exploit a SQL injection vulnerability in the `orderBy` query parameter of its REST API list endpoints. This flaw, which does not require authentication, allows for read-only blind extraction of data from the database.

A flaw was found in the maestro gRPC broker. This vulnerability allows a remote attacker, with a valid client certificate, to bypass authentication. This bypass enables the attacker to subscribe to other consumers' event streams, leading to unauthorized information disclosure, or to publish forged agent status, which can compromise data integrity.

A flaw was found in NetworkManager. This local privilege escalation vulnerability exists in NetworkManager's dhclient backend when processing malformed Manufacturer Usage Description (MUD) URLs. A local user can exploit this flaw to escalate privileges by triggering a script via a crafted MUD URL, provided an administrator has explicitly configured NetworkManager to use dhclient. This issue does not affect default configurations of NetworkManager.

ACM/MCE assisted-service writes raw referenced pull-secret contents into `InfraEnv.status.conditions[].message` when pull-secret validation fails. A namespace principal with the stock `view` ClusterRole cannot directly read Secrets, but can read `InfraEnv` objects and recover the referenced Secret's `.dockerconfigjson` data from status. This bypasses the Kubernetes/OpenShift RBAC separation between read-only namespace viewers and Secret readers. In the reproduced proof, the same ServiceAccount was denied `get` and `list` on Secrets, but recovered synthetic pull-secret `username`, `password`, `email`, and base64 `auth` fields through `InfraEnv.status`.

A vulnerability in the assisted-service REST API, an optional Assisted Installer (assisted-service) component in the Multicluster Engine (MCE), allows an authenticated user with minimal namespace-scoped privileges to obtain administrative credentials for arbitrary clusters provisioned through the hub. The credentials download endpoint (GET /v2/clusters/{cluster_id}/credentials, which returns the kubeadmin password) and the kubeconfig download endpoint are operational in AUTH_TYPE=local mode, the only authentication mode available in on-premises ACM/MCE hub deployments. The local authenticator unconditionally grants full administrative access to any request bearing a valid JWT, with no per-endpoint restrictions. A valid local JWT is embedded as a plaintext query parameter in InfraEnvStatus.ISODownloadURL and is readable by any user who has get rights on an InfraEnv object in their own namespace. The affected components ship as part of Multicluster Engine (MCE). The Red Hat Advanced Cluster Management (ACM) deployments that include MCE are equally affected. This issue does not affect the hosted SaaS offering (console.redhat.com), which uses a different authentication mode. Successful exploitation gives the attacker the kubeadmin password and kubeconfig for any OpenShift cluster provisioned through the affected hub, granting unrestricted root-level administrative access to those spoke clusters.

A container privilege escalation flaw was found in certain Multicluster Engine for Kubernetes images. This issue stems from the /etc/passwd file being created with group-writable permissions during build time. In certain conditions, an attacker who can execute commands within an affected container, even as a non-root user, can leverage their membership in the root group to modify the /etc/passwd file. This could allow the attacker to add a new user with any arbitrary UID, including UID 0, leading to full root privileges within the container.