An unauthenticated stack-based buffer overflow vulnerability exists in the HTTP API endpoint /cgi-bin/api.values.get. A remote attacker can leverage this vulnerability to achieve unauthenticated remote code execution (RCE) with root privileges on a target device. The vulnerability affects all six device models in the series: GXP1610, GXP1615, GXP1620, GXP1625, GXP1628, and GXP1630.
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.