CVE-2023-4473 : Security Advisory and Response

This CVE record was assigned by Zyxel and published on November 30, 2023. It pertains to a command injection vulnerability affecting Zyxel NAS326 firmware version V5.21(AAZF.14)C0 and NAS542 firmware version V5.21(ABAG.11)C0.

Understanding CVE-2023-4473

This section delves into the details surrounding CVE-2023-4473, shedding light on the vulnerability, its impact, technical aspects, and mitigation strategies.

What is CVE-2023-4473?

CVE-2023-4473 is a command injection vulnerability present in the web server of Zyxel NAS326 firmware version V5.21(AAZF.14)C0 and NAS542 firmware version V5.21(ABAG.11)C0. This vulnerability could allow an unauthorized attacker to execute operating system commands by sending a maliciously crafted URL to a vulnerable device.

The Impact of CVE-2023-4473

With a CVSS base score of 9.8 out of 10, CVE-2023-4473 is classified as critical. The vulnerability poses a high risk to confidentiality, integrity, and availability, making it crucial for organizations using the affected Zyxel products to address this issue promptly.

Technical Details of CVE-2023-4473

To better understand CVE-2023-4473, let's explore its vulnerability description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The command injection vulnerability in the Zyxel NAS326 and NAS542 firmware versions allows attackers to execute OS commands through specially crafted URLs, potentially compromising the affected devices.

Affected Systems and Versions

Zyxel NAS326 firmware version V5.21(AAZF.14)C0 and NAS542 firmware version V5.21(ABAG.11)C0 are confirmed to be impacted by CVE-2023-4473, exposing devices running these versions to the risk of exploitation.

Exploitation Mechanism

Attackers can exploit this vulnerability remotely via the network without requiring any user interaction. The low attack complexity combined with high impacts on confidentiality, integrity, and availability make it a potent threat.

Mitigation and Prevention

Addressing CVE-2023-4473 promptly is crucial to safeguard affected systems. Implementing immediate steps, adopting long-term security practices, and ensuring timely patching and updates are essential in mitigating the risks associated with this vulnerability.

Immediate Steps to Take

To mitigate the risks posed by CVE-2023-4473, users should consider implementing temporary workarounds, such as network segmentation or access control measures, to limit exposure to potential attacks.

Long-Term Security Practices

Enhancing network security measures, conducting regular vulnerability assessments, and staying informed about security advisories are fundamental practices to fortify the overall security posture and prevent similar incidents in the future.

Patching and Updates

Zyxel users are advised to apply patches provided by the vendor to address CVE-2023-4473. Regularly updating firmware and keeping abreast of security patches can help mitigate vulnerabilities and enhance the resilience of network infrastructure against potential threats.