icingaweb2-module-incubator is a working project of bleeding edge Icinga Web 2 libraries. In affected versions the class `gipfl\Web\Form` is the base for various concrete form implementations [1] and provides protection against cross site request forgery (CSRF) by default. This is done by automatically adding an element with a CSRF token to any form, unless explicitly disabled, but even if enabled, the CSRF token (sent during a client's submission of a form relying on it) is not validated. This enables attackers to perform changes on behalf of a user which, unknowingly, interacts with a prepared link or website. The version 0.22.0 is available to remedy this issue. Users are advised to upgrade. There are no known workarounds for this vulnerability.
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.