Zyxel Firewall Bricked by Buggy Update: On-Site Fix Required
2025-01-29
A faulty application signature update released by Zyxel last Friday is causing reboot loops, ZySH daemon failures, and login issues for some users. Affected devices include USG Flex and ATP Series devices running ZLD firmware with active security licenses and dedicated signature updates enabled in on-premises/standalone mode. The only workaround requires physical access to the firewall via a console/RS232 cable for recovery. Zyxel has disabled the application signature on its servers to prevent further impact.
Hardware
Software Bug