Grandstream Networks GXP1628 <=1.0.4.130 is vulnerable to Incorrect Access Control. The device is configured with directory listing enabled, allowing unauthorized access to sensitive directories and files.
Grandstream GXP1600 series firmware 1.0.4.152 and below is vulnerable to authenticated remote command execution when an attacker adds an OpenVPN up script to the phone's VPN settings via the "Additional Settings" field in the web interface. When the VPN's connection is established, the user defined script is executed with root privileges.
Grandstream GXP1600 series firmware 1.0.4.152 and below is vulnerable to authenticated remote command execution when an attacker uploads a specially crafted tar file to the HTTP /cgi-bin/upload_vpntar interface.