Red Hat Security Advisory: Red Hat Advanced Cluster Management for Kubernetes v2.16.4 security update

Important

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.

CWE-267 - Privilege Defined With Unsafe Actions

A flaw was found in form-data, a library for creating readable multipart/form-data streams. A remote attacker can exploit this vulnerability by injecting carriage return (CR), line feed (LF), or double-quote (") characters into the `field` argument of `FormData#append` or the `filename` option. This allows the attacker to inject additional headers or smuggle entire additional multipart parts into requests, potentially enabling them to add or override form fields and compromise data integrity.

CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')

A flaw was found in volsync-addon-controller. This vulnerability allows an attacker to inject malicious YAML (Yet Another Markup Language) code into the OpenShift Lifecycle Manager (OLM) Subscription resource. This is due to improper escaping of annotation values when they are rendered into YAML. Successful exploitation could lead to unauthorized modification or control over OLM Subscription configurations, potentially impacting software management within the cluster. This issue primarily affects systems where the 'volsync-addon-deploy-type: olm' annotation is explicitly enabled.

CWE-94 - Improper Control of Generation of Code ('Code Injection')

A flaw was found in the `crypto/x509` package of `golang`. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by presenting a specially crafted X.509 certificate with a large number of DNS Subject Alternative Name (SAN) entries. The certificate verification process, specifically the `VerifyHostname` function, incurs excessive computational overhead due to repeated string operations when processing these entries. This can lead to a significant performance degradation or unresponsiveness of systems validating such certificates.

CWE-606 - Unchecked Input for Loop Condition

A flaw was found in OpenTelemetry-Go. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by sending oversized or invalid baggage headers. The `Parse` function, in affected versions, failed to reject raw-length inputs, leading to excessive processing and error logging when handling these large inputs.

CWE-770 - Allocation of Resources Without Limits or Throttling