The Azure Blob Storage for Craft CMS plugin provides an Azure Blob Storage integration for Craft CMS. In versions on the 2.x branch prior to 2.1.1, unauthenticated users can view a list of buckets the plugin has access to. The DefaultController->actionLoadContainerData() endpoint allows unauthenticated users with a valid CSRF token to view a list of buckets that the plugin is allowed to see. Because Azure can return sensitive data in error messages, additional attack vectors are also exposed. Users should update to version 2.1.1 of the plugin to mitigate the issue.