Usg Flex Series Firmware
Monthly
Path traversal in Zyxel's ZLD-based firewall firmware (ATP, USG FLEX, USG FLEX 50(W), and USG20(W)-VPN series) allows an authenticated administrator to supply a crafted configuration file path to the CLI execution command, bypassing directory restrictions and achieving arbitrary code execution on the device. All four product lines share the same vulnerable CLI mechanism across wide firmware version ranges, substantially broadening the attack surface for organizations running unpatched appliances. No public exploit or CISA KEV listing has been identified at time of analysis, limiting immediate real-world risk to scenarios involving credential compromise or insider threat.
Path traversal in Zyxel's ZLD-based firewall firmware (ATP, USG FLEX, USG FLEX 50(W), and USG20(W)-VPN series) allows an authenticated administrator to supply a crafted configuration file path to the CLI execution command, bypassing directory restrictions and achieving arbitrary code execution on the device. All four product lines share the same vulnerable CLI mechanism across wide firmware version ranges, substantially broadening the attack surface for organizations running unpatched appliances. No public exploit or CISA KEV listing has been identified at time of analysis, limiting immediate real-world risk to scenarios involving credential compromise or insider threat.