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CVE-2023-27990

Published: Apr 24, 2023Updated: Feb 25, 2026 Sources: CVE List NVD BDUCWE-79
NVD MITRE
4.8CVSSMEDIUM
EPSS Score
0.3%
Top 74.0%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

The cross-site scripting (XSS) vulnerability in 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 with administrator privileges to store malicious scripts in a vulnerable device. A successful XSS attack could then result in the stored malicious scripts being executed when the user visits the Logs page of the GUI on the device.

CVSS Vector Breakdown

AV:NAC:LPR:HUI:RS:CC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:HPrivileges Required
High
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-79

Affected Products

ATP200Zyxel Communications Corp.Networking Infrastructure
ATP100Zyxel Communications Corp.Networking Infrastructure
ATP700Zyxel Communications Corp.Networking Infrastructure
ATP500Zyxel Communications Corp.Networking Infrastructure
ATP100WZyxel Communications Corp.Networking Infrastructure
zyxel communications corp.commercialTWNetworking Infrastructure
and 38 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Execution
Initial Access
View detailed technique mapping

References

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

Timeline

Published
Apr 24, 2023
Last Updated
Feb 25, 2026

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