CVE-2023-4473

A command injection vulnerability in the web server of the Zyxel NAS326 firmware version V5.21...

9.8 Critical

A command injection vulnerability in the web server of the Zyxel NAS326 firmware version V5.21(AAZF.14)C0 and NAS542 firmware version V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands by sending a crafted URL to a vulnerable device.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

41.3%Up 41.2 points since Dec 1, 2023

What each source reports

CVE List Score used 9.8

Record: CVE-2023-4473
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-78
Updated: 2026-11-02

EUVDEUVD-2023-54328 9.8

Record: EUVD-2023-54328
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-2h5j-5qmh-v4qh 9.8

A command injection vulnerability in the web server of the Zyxel NAS326 firmware version V5.21...

Record: GHSA-2h5j-5qmh-v4qh
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-78
Updated: 2026-11-02

NVD 9.8

Record: CVE-2023-4473
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-78
Updated: 2026-11-02

Affected products

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2023-4473 is a critical vulnerability (CVSS 9.8) in Zyxel Nas326 Firmware, published November 30, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 41.3%, the 98th percentile. No source names a fixed version.