Sangoma Technologies FreePBX before cdr 15.0.18, 16.0.40, 15.0.16, and 16.0.17 was discovered to contain an access control issue via a modified parameter value, e.g., changing extension=self to extension=101.
In Sangoma FreePBX 13 through 15 and sysadmin (aka System Admin) 13.0.92 through 15.0.13.6 modules have a Remote Command Execution vulnerability that results in Privilege Escalation.