Zyxel USG/ATP (ZLD)

Zyxel USG/ATP (ZLD) at a glance

Zyxel USG (and USG FLEX) are security gateway and firewall appliances popular with SMBs, running Zyxel's ZLD firmware. Zyxel ships firmware releases plus security fixes; as perimeter devices — and ones that have been actively targeted — prompt patching is essential.

For admins the priority is applying firmware security updates quickly: Zyxel gateways have been the subject of serious, actively exploited advisories, so a current firmware level is a real risk-reduction. Never expose the web management or SSL-VPN portal to the WAN unprotected, and disable unused remote-access services. Back up the configuration before updating, and in HA pairs mind the order. After updating, verify VPN tunnels, firewall rules and connectivity. Subscribe to Zyxel security advisories and act on them without delay — this vendor's appliances have a track record of exploited flaws. Patchletter surfaces new Zyxel firmware releases.