The SB6141 model Arris (formerly Motorola) SURFboard modem is vulnerable to unauthenticated reboot attacks due to two flaws. The flaws are easily patchable in theory, but they are not consumer-upgradable in practice. Arris has yet to create a firmware update that requires authentication before someone can use the UI to reboot or reset the modem. This process takes as long as a half hour to complete, though in some cases it could take an additional phone call to the internet service provider (ISP) to reactivate.”]
Source: https://grahamcluley.com/135-million-arris-modems-vulnerable-reboot-attacks/