app/operator_panel/exec.php in the Operator Panel module in FusionPBX 4.4.3 suffers from a command injection vulnerability due to a lack of input validation that allows authenticated non-administrative attackers to execute commands on the host. This can further lead to remote code execution when combined with an XSS vulnerability also present in the FusionPBX Operator Panel module.
https://github.com/fusionpbx/fusionpbx/commit/e43ca27ba2d9c0109a6bf198fe2f8d79f63e0611
http://packetstormsecurity.com/files/155344/FusionPBX-Operator-Panel-exec.php-Command-Execution.html
http://packetstormsecurity.com/files/153256/FusionPBX-4.4.3-Remote-Command-Execution.html