Grandstream Phone Vulnerability Security Issue Remote Backdoor Connection to

Have you checked your router/firewall logs and disconcertingly see connections to an unknown IP from your Grandstream VOIP phones?

You're not alone and the Grandstream forums have discussed this issue.

However, even their own staff do not seem to be aware or are not disclosing what this connection is.

It is Grandstream's UCM Remote connect feature

This is the establishment to the STUN server and you can find their list of servers/info here.

It allows you to remotely provision and manage your devices and is enabled by default at least on later/newer firmware versions.  While this is a great feature and helpful for provisioning, it is still concerning since there is no obvious warning or disclosure on this when purchasing the phone.  It represents a huge tradeoff of security/privacy vs convenience.

The concern is that Grandstream, the government and hackers could potentially compromise your phone, your calls and even your network is it is essentially a back door to your network despite being on a protected LAN and firewall.  Others share the same concern here:


How To Disable The Remote 3478 Connection

Under "Advanced Settings" -> Enable TR-069 disable it by setting to to "No" and then click "Apply".


Manual Edit Cannot Disable

You can remove the P8209 entry or make it null or change it, and upload the config file, but the firmware seems to just default back and re-enable the STUN server.  The only solution is to block any DNS lookups to that host and block all traffic to that UDP port.


grandstream, vulnerability, backdoor, router, firewall, logs, disconcertingly, connections, ip, voip, forums, disclosing, gdms, ucm, feature, establishment, stun, server, servers, info, allows, remotely, provision, devices, enabled, default, newer, firmware, versions, concerning, disclosure, purchasing, disabled, admin, config, entry, null, upload, enable, dns, lookups, udp,

Latest Articles

  • qemu: could not load PC BIOS 'bios-256k.bin' solution
  • Proxmox How To Custom Partition During Install
  • Hyper-V Linux VM Boots to Black Screen, Storage, NIC Not Found Issues
  • Ubuntu Mint How to Fix Missing/Broken /dev and /dev/pts which causes terminal to immediately close exit and not work
  • How high can a Xeon CPU get?
  • bash fix PATH environment variable "command not found" solution
  • Ubuntu Linux Mint Debian Redhat Youtube Cannot Play HD or 4K videos, dropped frames or high CPU usage with Nvidia or AMD Driver
  • hostapd example configuration for high speed AC on 5GHz using WPA2
  • hostapd how to enable and use WPS to connect wireless devices like printers
  • Dell Server Workstation iDRAC Dead after Firmware Update Solution R720, R320, R730
  • Cloned VM/Server/Computer in Linux won't boot and goes to initramfs busybox Solution
  • How To Add Windows 7 8 10 11 to GRUB Boot List Dual Booting
  • How to configure OpenDKIM on Linux with Postfix and setup bind zonefile
  • Debian Ubuntu 10/11/12 Linux how to get tftpd-hpa server setup tutorial
  • efibootmgr: option requires an argument -- 'd' efibootmgr version 15 grub-install.real: error: efibootmgr failed to register the boot entry: Operation not permitted.
  • Apache Error Won't start SSL Cert Issue Solution Unable to configure verify locations for client authentication SSL Library Error: 151441510 error:0906D066:PEM routines:PEM_read_bio:bad end line SSL Library Error: 185090057 error:0B084009:x509 certif
  • Linux Debian Mint Ubuntu Bridge br0 gets random IP
  • redis requirements
  • How to kill a docker swarm
  • docker swarm silly issues