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 object-level authorization on `/notification/export/{id}` allows an authenticated user to download attachments from any notification, including notifications created by administrators, by iterating over `sequential notification IDs`. Exploitation requires access to the `Notification Centre` to view past notifications, a privilege granted to non-administrators as standard. This issue is fixed in version 4.4.3.
https://github.com/xibosignage/xibo-cms/security/advisories/GHSA-p4pg-v57g-7jf6
https://github.com/xibosignage/xibo-cms/releases/tag/4.5.0-beta
https://github.com/xibosignage/xibo-cms/releases/tag/4.4.3
https://github.com/xibosignage/xibo-cms/pull/3487
https://github.com/xibosignage/xibo-cms/commit/1dcc3f2de6dc7861e7dbb5148e94f14ebb1513b3
https://github.com/xibosignage/xibo-cms/commit/13ed6e6bf3c15a93089b4fd2148379888ee82d74