CVE-2023-34138 : Security Advisory and Response
Learn about CVE-2023-34138, a high-severity command injection vulnerability in Zyxel firmware versions 4.60 through 5.36 Patch 2. Understand the impact, affected systems, and mitigation steps.
A command injection vulnerability in multiple Zyxel firmware versions could allow an attacker to execute OS commands. Here's what you need to know about CVE-2023-34138.
Understanding CVE-2023-34138
This section provides insights into the vulnerability's nature, impact, and affected systems.
What is CVE-2023-34138?
The CVE-2023-34138 is a command injection vulnerability present in various Zyxel firmware versions, including ATP series, USG FLEX series, USG FLEX 50(W) series, USG20(W)-VPN series, and VPN series. This vulnerability could enable an unauthenticated attacker to execute OS commands on a device.
The Impact of CVE-2023-34138
The vulnerability poses a high risk with a CVSS base score of 8, impacting confidentiality, integrity, and availability. An attacker could exploit this flaw to execute arbitrary commands on the affected device.
Technical Details of CVE-2023-34138
This section delves into the specifics of the vulnerability, affected systems, and the exploitation mechanism.
Vulnerability Description
The vulnerability resides in the hotspot management feature of the Zyxel firmware versions 4.60 through 5.36 Patch 2. It allows an unauthenticated LAN-based attacker to run OS commands by manipulating the list of trusted RADIUS clients.
Affected Systems and Versions
The vulnerability affects Zyxel ATP series, USG FLEX series, USG FLEX 50(W) series, USG20(W)-VPN series, and VPN series firmware versions 4.60 through 5.36 Patch 2.
Exploitation Mechanism
To exploit the vulnerability, an attacker needs to trick an authorized administrator into adding their IP address to the list of trusted RADIUS clients, enabling the execution of malicious commands.
Mitigation and Prevention
Learn more about mitigating the risk associated with CVE-2023-34138 and securing your systems.
Immediate Steps to Take
It is crucial to update the affected firmware versions to patched releases immediately. Additionally, restrict access to sensitive systems and regularly monitor for unauthorized activities.
Long-Term Security Practices
Implement network segmentation, strong access controls, and least privilege principles. Conduct regular security training for administrators to prevent social engineering attacks.
Patching and Updates
Stay informed about security advisories from Zyxel and apply patches promptly. Regularly update and patch all network devices to prevent exploitation of known vulnerabilities.