CVE-2023-22921Network attack vector

Service interruption via stored management-interface scripts

Published May 1, 2023 · Updated Jan 30, 2025

Stored XSS in Zyxel NBG-418N v2 firmware before 1.00(AARP.14)C0 allows remote authenticated users to interrupt device service. The web management interface accepts a parameter containing attacker-supplied script and stores it without adequate output neutralization. Administrator privileges and user interaction are required; WAN management is disabled by default, and successful execution can deny device service.

CVSS severity7.5
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Zyxel NBG-418N v2 firmware before 1.00(AARP.14)C0 allows remote authenticated users to interrupt device service. The web management interface accepts a parameter containing attacker-supplied script and stores it without adequate output neutralization. Administrator privileges and user interaction are required; WAN management is disabled by default, and successful execution can deny device service.

The record

CVE
CVE-2023-22921
Published
May 1, 2023
Updated
Jan 30, 2025
Vendor
Zyxel Networks
Product
NBG-418N v2 firmware
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. May 1, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 30, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< V1.00(AARP.14)C0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Zyxel Networks · NBG-418N v2 firmwareversion=< V1.00(AARP.14)C0

Published CVSS scores

7.5Zyxel CorporationCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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