Security expert David Longenecker reported security vulnerabilities affecting the popular broadband cable SURFboard modems produced by the ARRIS (formerly Motorola) More than 135 million devices are at risk. Attackers can exploit the flaws to remotely knock out the device for a period of time that could reach 30 minutes. The good news is that the vulnerabilities are easy to patch, the vendor just needs to issue a firmware update that implements an authentication mechanism for the reboot and reset of the cable modems, and implement a mechanism to prevent CSRF attacks.”]
Source: https://securityaffairs.co/wordpress/46117/hacking/arris-cable-modems-attack.html