Grandstream HT800 series firmware version 1.0.17.5 and below is vulnerable to an OS command injection vulnerability. Unauthenticated remote attackers can execute arbitrary commands as root by crafting a special configuration file and sending a crafted SIP message.

Grandstream HT800 series firmware version 1.0.17.5 and below contain a backdoor in the SSH service. An authenticated remote attacker can obtain a root shell by correctly answering a challenge prompt.

Grandstream HT800 series firmware version 1.0.17.5 and below is vulnerable to CPU exhaustion due to an infinite loop in the TR-069 service. Unauthenticated remote attackers can trigger this case by sending a one character TCP message to the TR-069 service.

Grandstream HT800 series firmware version 1.0.17.5 and below is vulnerable to a denial of service attack against the TR-069 service. An unauthenticated remote attacker can stop the service due to a NULL pointer dereference in the TR-069 service. This condition is triggered due to mishandling of the HTTP Authentication field.