XSS in app/operator_panel/index_inc.php in the Operator Panel module in FusionPBX 4.4.3 allows remote unauthenticated attackers to inject arbitrary JavaScript characters by placing a phone call using a specially crafted caller ID number. This can further lead to remote code execution by chaining this vulnerability with a command injection vulnerability also present in FusionPBX.
https://github.com/fusionpbx/fusionpbx/commit/391a23d070f3036d0c7760992f6970b0a76ee4d7
http://packetstormsecurity.com/files/153256/FusionPBX-4.4.3-Remote-Command-Execution.html