The Stream plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 4.0.1. This is due to missing or incorrect nonce validation on the network_options_action() function. This makes it possible for unauthenticated attackers to update arbitrary options that can lead to DoS or privilege escalation via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.