High severity · published Oct 21, 2025
CVE-2025-9133
A missing authorization vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions from V4.50 through V5.40, USG FLEX 50(W)…
8.1
CVSS
5.5%
EPSS
No
On KEV
Description
A missing authorization vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions from V4.50 through V5.40, USG FLEX 50(W) series firmware versions from V4.16 through V5.40, and USG20(W)-VPN series firmware versions from V4.16 through V5.40 could allow a semi-authenticated attacker—who has completed only the first stage of the two-factor authentication (2FA) process—to view and download the system configuration from an affected device.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)5.5% · higher than 93% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZL
Zld · Zyxel
4.32 before 5.41; 4.50 before 5.41; 4.16 before 5.41 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-9133
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-9133
Vendor Advisory
https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-post-authentication-command-injection-and-missing-authorization-vulnerabilities-in-zld-firewalls-10-21-2025
More from Zld
9.8
CVE-2024-11667
Zyxel Multiple Firewalls Path Traversal Vulnerability
9.8
CVE-2020-25014
A stack-based buffer overflow in fbwifi_continue.cgi on Zyxel UTM and VPN series of gateways running firmware version V4.30 through to V4.55 allows remote unauthenticated…
8.1
CVE-2024-42057
A command injection vulnerability in the IPSec VPN feature of Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through…
7.5
CVE-2024-42058
A null pointer dereference vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through V5.38, USG FLEX 50(W)…
7.5
CVE-2023-4398
An integer overflow vulnerability in the source code of the QuickSec IPSec toolkit used in the VPN feature of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX…