Zyxel Vulnerability Tracker.

This page holds short security alerts about vulnerabilities in Zyxel products. It covers 3 items from April 2022 to February 2023. Each entry keeps its original title, publish date and text, newest first and grouped by quarter. Earlier addresses of these entries now lead to the matching entry here.

2023 Q1

Zyxel Issues Critical Vulnerability Alert For Certain Router Models

Published 28 February 2023CVE-2023-229204G LTE Routers

Zyxel has released security updates addressing a critical security vulnerability affecting 4G LTE indoor routers. The vulnerability affects two router models, LTE3202-M437 and LTE3316-M604.

Tracked as CVE-2023-22920, the vulnerability could allow a remote threat actor to gain unauthorized access to a vulnerable system where a factory-default misconfiguration is present. By using Telnet, the threat actor could exploit this vulnerability and gain unauthorized access to the affected device.

The vulnerability affects the following impacted models and versions:

Zyxel has released security updates

Zyxel has released security updates addressing the vulnerability. Users of impacted models and versions are strongly advised to apply the published updates as soon as possible to avoid potential exploitation of the vulnerability.

2022 Q4

Critical XSS Alert Affecting Zyxel’s Specific Firewall Models

Published 6 December 2022CVE-2022-40603Firewalls

Zyxel has released updates for a critical XSS (Cross Site Scripting) vulnerability that affects specific models of firewalls.

The vulnerability, tracked as CVE-2022-40603, affects the CGI program of firewall versions and is caused by insufficient sanitization of user-supplied data. A remote threat actor can direct targeted users to visit an XSS-loaded URL and execute a malicious script in the user’s browser. A threat actor who successfully exploited the vulnerability could access sensitive browser-based information.

The firewall models and versions affected by the security vulnerability are as follows;

• Zyxel has fixed the said vulnerability with the current versions mentioned above. In this context, it is recommended to implement the published updates immediately in order not to be the target of targeted attacks that can be carried out using the vulnerability.

2022 Q2

Zyxel Released Updates To Fixing A Critical Vulnerability

Published 4 April 2022CVE-2022-0342FirewallsVPN

Zyxel has released security updates for a critical security vulnerability affecting business firewall and VPN solutions.

The security vulnerability tracked by code CVE-2022-0342 is an authentication bypass vulnerability caused by the lack of a proper access control mechanism in the web interface of some firewall versions. A threat actor that successfully exploits the vulnerability can bypass authentication and gain access to administrative privileges on the vulnerable system. The vulnerability affects the versions listed below.

Zyxel stated that no evidence of active exploitation of the said vulnerability has been detected yet and has released updates that fix the vulnerability. In this context, it is recommended that updates that fix the vulnerability be applied immediately to avoid the attacks that can be carried out using the vulnerability.