CVE-2023-22913 : Security Advisory and Response

This CVE, assigned by Zyxel, was published on April 24, 2023. It involves a post-authentication command injection vulnerability in the "account_operator.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. This vulnerability could potentially allow a remote authenticated attacker to modify device configuration data, leading to denial-of-service (DoS) conditions on the affected device.

Understanding CVE-2023-22913

Let's delve deeper into the details of CVE-2023-22913.

What is CVE-2023-22913?

CVE-2023-22913 is a post-authentication command injection vulnerability found in specific Zyxel firmware versions, allowing a remote authenticated attacker to manipulate device configuration data.

The Impact of CVE-2023-22913

The impact of this vulnerability is significant as it can result in denial-of-service (DoS) conditions on affected devices, potentially disrupting their normal operations and availability.

Technical Details of CVE-2023-22913

To better understand CVE-2023-22913, let's explore its technical aspects.

Vulnerability Description

The vulnerability in the "account_operator.cgi" CGI program allows attackers to inject commands post-authentication, giving them unauthorized access to modify device configurations, leading to a denial-of-service scenario.

Affected Systems and Versions

The Zyxel USG FLEX series firmware versions 4.50 through 5.35 and VPN series firmware versions 4.30 through 5.35 are affected by this vulnerability, making devices running these versions susceptible to exploitation.

Exploitation Mechanism

Attackers having remote authenticated access can exploit this vulnerability by injecting malicious commands through the affected CGI program, potentially causing disruptions and unauthorized modifications to device settings.

Mitigation and Prevention

Protecting systems from CVE-2023-22913 requires immediate action and long-term security practices.

Immediate Steps to Take

Organizations should apply security patches provided by Zyxel promptly to mitigate the vulnerability.
Implement network segmentation and access controls to limit the impact of potential attacks targeting this vulnerability.
Monitor network traffic and device configurations for any signs of unauthorized access or modifications.

Long-Term Security Practices

Regularly update firmware and software to ensure systems are equipped with the latest security enhancements.
Conduct routine security assessments and penetration testing to identify and address vulnerabilities proactively.
Educate users and administrators on best practices for securing network devices and maintaining vigilance against potential threats.

Patching and Updates

Zyxel has released patches to address CVE-2023-22913. It is crucial for organizations using affected firmware versions to apply these patches as soon as possible to safeguard their devices against exploitation.