CVE-2023-27992

Name: CVE-2023-27992
Creator: NVD / NIST
Published: 2023-06-19T12:15:09.433+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10Actively ExploitedEPSS 84.27%

Last modified Jun 17, 2026

CVE-2023-27992 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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 has confirmed active exploitation in the wild. EPSS estimates a 84.27% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

84.27%

99.7th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Jul 14, 2023.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Zyxel	Nas326 Firmware	< 5.21\(aazf.14\)c0
Zyxel	Nas540 Firmware	< 5.21\(aatb.11\)c0
Zyxel	Nas542 Firmware	< 5.21\(abag.11\)c0

References

Timeline

Published: Jun 19, 2023
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2023-27992?

How severe is CVE-2023-27992?

CVE-2023-27992 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 84.27% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2023-27992?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-27992?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST