CVE-2023-27992

CRITICAL KEV

Zyxel NAS326, NAS540, and NAS542 Firmware < 5.21 - Unauthenticated OS Command Injection via HTTP Request

Title source: llm

Exploitation Summary

CVE-2023-27992 is actively exploited and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added June 23, 2023.

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.

References (2)

Core 2

Core References

Patch, Vendor Advisory

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products

US Government Resource

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27992

Scores

CVSS v3 9.8

EPSS 0.8762

EPSS Percentile 99.5%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation active

Automatable yes

Technical Impact total

Details

CISA KEV 2023-06-23

VulnCheck KEV 2023-06-23

InTheWild.io 2023-06-23

ENISA EUVD EUVD-2023-31717

CWE

CWE-78

Status published

Products (3)

zyxel/nas326_firmware < 5.21\(aazf.14\)c0

zyxel/nas540_firmware < 5.21\(aatb.11\)c0

zyxel/nas542_firmware < 5.21\(abag.11\)c0

Published Jun 19, 2023

KEV Added Jun 23, 2023

Tracked Since Feb 18, 2026