Missing Authorization Vulnerability in Zyxel ATP and USG FLEX Products
CVE-2025-9133

8.1HIGH

Key Information:

Vendor

Zyxel
Status
Atp Series Firmware
Usg Flex Series Firmware
Usg Flex 50(w) Series Firmware
Usg20(w)-vpn Series Firmware
Vendor
CVE Published:
21 October 2025

What is CVE-2025-9133?

A missing authorization vulnerability in specific firmware versions of Zyxel ATP and USG FLEX series allows semi-authenticated attackers—those who have only partially completed two-factor authentication (2FA)—to access and download sensitive system configuration details from affected devices. This could lead to a serious compromise of device integrity and user privacy, underscoring the importance of robust authorization mechanisms in modern security products.

Affected Version(s)

ATP series firmware versions from V4.32 through V5.40

USG FLEX 50(W) series firmware versions from V4.16 through V5.40

USG FLEX series firmware versions from V4.50 through V5.40

References

https://www.zyxel.com/global/en/support/security-advisori...
vendor-advisory

CVSS V3.1

Score:
8.1
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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