The Sangoma Session Border Controller (SBC) 2.3.23-119 GA web interface is vulnerable to Argument Injection via special characters in the username field. Upon successful exploitation, a remote unauthenticated user can create a local system user with sudo privileges, and use that user to login to the system (either via the web interface or via SSH) to achieve complete compromise of the device. This affects /var/webconfig/gui/Webconfig.inc.php and /usr/local/sng/bin/sng-user-mgmt.