Xibo: IDOR (Broken Object-Level Authorization) on PUT/DELETE /action/{id} Allows Arbitrary Layout Action Modification and Deletion

Xibo is an open source digital signage platform with a web content management system and Windows display player software. Prior to 4.4.3, missing access-control checks on `PUT/DELETE /action/{id}` allow an authenticated user to modify or delete actions on any Layout. Exploitation requires the privilege to allow edits, including deletion, to all created Layouts, which is granted to non-administrators as standard. This issue concerns `Layout actions` rather than the separately reported DataSet export vulnerability. This issue is fixed in version 4.4.3.