Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. All unpatched versions of Argo CD starting with 1.0.0 are vulnerable to an improper access control bug, allowing a malicious user to potentially escalate their privileges to admin-level. Versions starting with 0.8.0 and 0.5.0 contain limited versions of this issue. To perform exploits, an authorized Argo CD user must have push access to an Application's source git or Helm repository or `sync` and `override` access to an Application. Once a user has that access, different exploitation levels are possible depending on their other RBAC privileges. A patch for this vulnerability has been released in Argo CD versions 2.3.2, 2.2.8, and 2.1.14. Some mitigation measures are available but do not serve as a substitute for upgrading. To avoid privilege escalation, limit who has push access to Application source repositories or `sync` + `override` access to Applications; and limit which repositories are available in projects where users have `update` access to Applications. To avoid unauthorized resource inspection/tampering, limit who has `delete`, `get`, or `action` access to Applications.

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. Versions starting with 2.5.0-rc1 and above, prior to 2.5.8, and version 2.6.0-rc4, are vulnerable to an authorization bypass bug which allows a malicious Argo CD user to deploy Applications outside the configured allowed namespaces. Reconciled Application namespaces are specified as a comma-delimited list of glob patterns. When sharding is enabled on the Application controller, it does not enforce that list of patterns when reconciling Applications. For example, if Application namespaces are configured to be argocd-*, the Application controller may reconcile an Application installed in a namespace called other, even though it does not start with argocd-. Reconciliation of the out-of-bounds Application is only triggered when the Application is updated, so the attacker must be able to cause an update operation on the Application resource. This bug only applies to users who have explicitly enabled the "apps-in-any-namespace" feature by setting `application.namespaces` in the argocd-cmd-params-cm ConfigMap or otherwise setting the `--application-namespaces` flags on the Application controller and API server components. The apps-in-any-namespace feature is in beta as of this Security Advisory's publish date. The bug is also limited to Argo CD instances where sharding is enabled by increasing the `replicas` count for the Application controller. Finally, the AppProjects' `sourceNamespaces` field acts as a secondary check against this exploit. To cause reconciliation of an Application in an out-of-bounds namespace, an AppProject must be available which permits Applications in the out-of-bounds namespace. A patch for this vulnerability has been released in versions 2.5.8 and 2.6.0-rc5. As a workaround, running only one replica of the Application controller will prevent exploitation of this bug. Making sure all AppProjects' sourceNamespaces are restricted within the confines of the configured Application namespaces will also prevent exploitation of this bug.