Zyxel VMG4325-B10A Command Injection Vulnerability in Legacy DSL CPE

A post-authentication command injection vulnerability has been identified in the CGI program of the Zyxel VMG4325-B10A DSL CPE, running firmware version 1.00(AAFR.4)C0_20170615. This vulnerability allows authenticated attackers to execute operating system commands on the affected device by sending a crafted HTTP POST request. The issue arises because the device's default WAN access is disabled, meaning the attack can only be successful if user-configured passwords have been compromised.

Impact

Exploitation of this vulnerability could lead to unauthorized execution of operating system commands on the affected device.

Remediation

Zyxel advises users to replace legacy products like the VMG4325-B10A with newer-generation equipment. For those who obtained their Zyxel device through an internet service provider, please contact the ISP for support.