FusionPBX 5.0.1 was discovered to contain a command injection vulnerability via /fax/fax_send.php.
https://github.com/fusionpbx/fusionpbx/commit/de22a9121a091e7fedddff22329dd6149dc5ab28
https://github.com/fusionpbx/fusionpbx/commit/07679fe80dadb08ca23d0fc16c0f832348bfec78