A flaw was found in the Application Subscription controller (multicluster-operators-subscription) of Red Hat Advanced Cluster Management for Kubernetes (ACM). A user with namespace-scoped "edit" privileges in an ACM hub namespace can create a Channel resource pointing to a Helm repository they control and a Subscription resource referencing it. The app-subscription controller fetches and applies the Helm chart contents with its own elevated authority, without verifying whether the subscription creator holds the "open-cluster-management:subscription-admin" role and without restricting applied resources to the subscription namespace. This allows the attacker to include cluster-scoped resources in the Helm chart, such as a ClusterRoleBinding granting the attacker's ServiceAccount the "cluster-admin" ClusterRole. Successful exploitation results in full cluster-admin privilege escalation. This contradicts the ACM documentation which states that non-subscription-admin users should have resources deployed into the subscription namespace only.

A flaw was found in the Application Subscription controller (multicluster-operators-subscription) of Red Hat Advanced Cluster Management for Kubernetes (ACM). A user with namespace-scoped "edit" privileges in an ACM hub namespace can create a Channel resource pointing to a Helm repository they control and a Subscription resource referencing it. The app-subscription controller fetches and applies the Helm chart contents with its own elevated authority, without verifying whether the subscription creator holds the "open-cluster-management:subscription-admin" role and without restricting applied resources to the subscription namespace. This allows the attacker to include cluster-scoped resources in the Helm chart, such as a ClusterRoleBinding granting the attacker's ServiceAccount the "cluster-admin" ClusterRole. Successful exploitation results in full cluster-admin privilege escalation. This contradicts the ACM documentation which states that non-subscription-admin users should have resources deployed into the subscription namespace only.

multicluster-operators-subscription: multicluster-operators-subscription: namespace edit user can deploy cluster-scoped ClusterRoleBinding and become cluster-admin via Application Subscription fast-uri: fast-uri: Security policy bypass due to improper Unicode hostname canonicalization github.com/hashicorp/memberlist: HashiCorp memberlist: Denial of Service via push/pull state handling volsync-addon-controller: volsync-addon-controller: annotation values rendered into YAML via text/template without escaping allows YAML injection into Subscription golang.org/x/net/html: golang: golang.org/x/net/html: Cross-Site Scripting via HTML parsing bypass crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries grafana: Grafana: Privilege escalation via dashboard overwrite github.com/prometheus/prometheus: Prometheus: Information disclosure of Azure OAuth client secret via config API github.com/prometheus/prometheus: Prometheus: Denial of Service via uncontrolled memory allocation in remote read endpoint golang.org/x/net/html: golang: golang.org/x/net/html: Cross-Site Scripting via unexpected HTML tree rendering github.com/go-git/go-billy: Billy: Denial of Service via crafted input due to insufficient validation sanitize-html: `sanitize-html`: Stored Cross-Site Scripting via HTML sanitizer bypass postcss: PostCSS: Information disclosure and denial of service via crafted CSS input github.com/hamba/avro/v2: github.com/linkedin/goavro/v2: Intege…