An FBX-5312 issue was discovered in WatchGuard Fireware before 12.0. If a login attempt is made in the XML-RPC interface with an XML message containing an empty member element, the wgagent crashes, logging out any user with a session opened in the UI. By continuously executing the failed login attempts, UI management of the device becomes impossible.

An FBX-5313 issue was discovered in WatchGuard Fireware before 12.0. When a failed login attempt is made to the login endpoint of the XML-RPC interface, if JavaScript code, properly encoded to be consumed by XML parsers, is embedded as value of the user element, the code will be rendered in the context of any logged in user in the Web UI visiting "Traffic Monitor" sections "Events" and "All." As a side effect, no further events will be visible in the Traffic Monitor until the device is restarted.