In FusionPBX up to v4.5.7, the file app\devices\device_settings.php uses an unsanitized "id" variable coming from the URL, which is reflected on 2 occasions in HTML, leading to XSS.
https://resp3ctblog.wordpress.com/2019/10/19/fusionpbx-xss-11/
https://github.com/fusionpbx/fusionpbx/commit/83622c4ee1d9dd1913e9fb01ce8f060b46a5768a