CVE-2023-22914 : Exploit Details and Defense Strategies

A path traversal vulnerability in the "account_print.cgi" CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, and VPN series firmware versions 4.30 through 5.35 has been identified. This vulnerability could potentially allow a remote authenticated attacker with administrator privileges to execute unauthorized OS commands in the "tmp" directory by uploading a crafted file if the hotspot function were enabled.

Understanding CVE-2023-22914

This section delves into the details of CVE-2023-22914, shedding light on the vulnerability, its impact, technical aspects, and mitigation strategies.

What is CVE-2023-22914?

CVE-2023-22914 is a path traversal vulnerability found in Zyxel USG FLEX series firmware versions 4.50 through 5.35 and VPN series firmware versions 4.30 through 5.35. This vulnerability could be exploited by a remote authenticated attacker with administrator privileges to run unauthorized OS commands in the "tmp" directory by uploading a specifically crafted file when the hotspot function is activated.

The Impact of CVE-2023-22914

The impact of CVE-2023-22914 is significant, as it could lead to a remote attacker gaining unauthorized access and executing commands within the system, potentially causing damage to confidentiality, integrity, and availability of the affected systems.

Technical Details of CVE-2023-22914

This section provides a detailed overview of the vulnerability, including its description, affected systems, and the exploitation mechanism.

Vulnerability Description

The vulnerability arises from improper input validation in the "account_print.cgi" CGI program, allowing an attacker to traverse directories and execute arbitrary OS commands by uploading a malicious file to the "tmp" directory.

Affected Systems and Versions

Vendor: Zyxel
Affected Products:
USG FLEX series firmware versions 4.50 through 5.35
VPN series firmware versions 4.30 through 5.35

Exploitation Mechanism

An authenticated attacker with administrator privileges can exploit this vulnerability by uploading a specially crafted file through the "account_print.cgi" CGI program when the hotspot function is enabled, leading to the execution of unauthorized OS commands in the system.

Mitigation and Prevention

In light of CVE-2023-22914, it is crucial to implement immediate steps to address the vulnerability and adopt long-term security practices to enhance the resilience of systems against similar threats.

Immediate Steps to Take

Disable the hotspot function on Zyxel USG FLEX and VPN series devices to mitigate the risk of exploitation.
Monitor network traffic for any suspicious activities that may indicate an attempted attack.
Apply security patches released by Zyxel to fix the vulnerability and strengthen system defenses.

Long-Term Security Practices

Regularly update firmware and security patches provided by Zyxel to protect against known vulnerabilities.
Conduct security audits and penetration testing to identify and address potential weaknesses in the network infrastructure.
Educate system administrators and users on best security practices to prevent unauthorized access and malicious activities.

Patching and Updates

Zyxel has released firmware updates to address the CVE-2023-22914 vulnerability. It is recommended to promptly apply these patches to ensure the security and integrity of the affected systems.