CVE-2023-27991

HIGH

Zyxel ATP/USG FLEX/USG20W-VPN/VPN Firmware - Authenticated OS Command Injection via CLI Command

Title source: llm

Description

The post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow an authenticated attacker to execute some OS commands remotely.

References (1)

Core 1

Core References

Vendor Advisory

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-xss-vulnerability-and-post-authentication-command-injection-vulnerability-in-firewalls

Scores

CVSS v3 8.8

EPSS 0.0158

EPSS Percentile 81.8%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

Details

CWE

CWE-78

Status published

Products (19)

zyxel/atp100_firmware 4.32 - 5.36

zyxel/atp100w_firmware 4.32 - 5.36

zyxel/atp200_firmware 4.32 - 5.36

zyxel/atp500_firmware 4.32 - 5.36

zyxel/atp700_firmware 4.32 - 5.36

zyxel/atp800_firmware 4.32 - 5.36

zyxel/usg20-vpn_firmware 4.30 - 5.36

zyxel/usg_20w-vpn_firmware 4.16 - 5.36

zyxel/usg_flex_100_firmware 4.50 - 5.36

zyxel/usg_flex_100w_firmware 4.50 - 5.36

... and 9 more

Published Apr 24, 2023

Tracked Since Feb 18, 2026