# CVE-2023-27992: Zyxel Multiple NAS Devices Command Injection Vulnerability

> CVE-2023-27992: Zyxel Multiple NAS Devices Command Injection Vulnerability. CVSS 9.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2023-27992
Last updated: 2025-10-21T23:05:45Z

- Published: 2023-06-19 11:42 UTC · Updated: 2025-10-21 23:05 UTC · Assigner: Zyxel
- CVSS: 9.8 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 82.3%, 100th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2023-06-23, federal due date 2023-07-14, ransomware use: Unknown
- CWE: CWE-78

## Description

The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware versions prior to V5.21(AATB.11)C0, and NAS542 firmware versions prior to V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands remotely by sending a crafted HTTP request.

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- Zyxel: NAS326 firmware
- Zyxel: NAS540 firmware
- Zyxel: NAS542 firmware

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2023-27992)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2023-27992)
- [https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products](https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2023-27992 · Markdown: https://rewindex.com/cve/CVE-2023-27992.md · JSON: https://rewindex.com/api/v1/cves/CVE-2023-27992 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:13:20.069Z