GStreamer Editing Services: project files can run arbitrary pipeline elements

A flaw was found in GStreamer Editing Services (gst-editing-services). A GES project file can embed an arbitrary GStreamer pipeline description as an effect definition. When such a file is loaded, either explicitly by an editing application or automatically by a media player or file-manager thumbnailing service that uses GStreamer autoplugging, the pipeline description is parsed and instantiated without restriction on which elements may be used or which properties may be set. A remote attacker who can deliver a crafted project file to a victim's system can trigger reading or writing of arbitrary local files, issue outbound network requests to attacker-controlled servers, or cause the application to crash. Under certain conditions the file-write capability may be leveraged to achieve code execution.