Zyxel DSL CPE Command Injection Vulnerability in VMG4325-B10A

A post-authentication command injection vulnerability has been identified in the management commands of the Zyxel VMG4325-B10A DSL CPE model, specifically in the firmware version 1.00(AAFR.4)C0_20170615. This vulnerability allows an authenticated attacker to execute operating system commands on the affected device via Telnet. However, it is important to note that WAN access and the Telnet function are disabled by default on these devices. Exploitation of this vulnerability would require knowledge of the user-configured passwords, which, if compromised, could lead to unauthorized command execution on the device.

Impact

Exploitation of this vulnerability could result in unauthorized execution of operating system commands on the affected device via Telnet.

Remediation

Zyxel advises users to replace legacy products like the VMG4325-B10A with newer-generation equipment for optimal protection. For those who obtained their Zyxel product through an internet service provider, it is recommended to contact the ISP for support. Additionally, disabling remote access and periodically changing passwords can help prevent potential attacks.