CVE-2022-43389Network attack vector

OS command execution via web-server buffer overflow

Published Jan 11, 2023 · Updated Apr 9, 2025

Classic buffer overflow in the web-server library of Zyxel NR7101 firmware before V1.15(ACCC.3)C0 allows remote attackers to run OS commands. The library copies attacker-controlled input without checking its size, overflowing the destination buffer. No authentication is required; exploitation executes commands or crashes the device, while WAN access is disabled by default on most devices.

CVSS severity8.6
High
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Classic buffer overflow in the web-server library of Zyxel NR7101 firmware before V1.15(ACCC.3)C0 allows remote attackers to run OS commands. The library copies attacker-controlled input without checking its size, overflowing the destination buffer. No authentication is required; exploitation executes commands or crashes the device, while WAN access is disabled by default on most devices.

The record

CVE
CVE-2022-43389
Published
Jan 11, 2023
Updated
Apr 9, 2025
Vendor
Zyxel Networks
Product
NR7101 Firmware
Classifications
CWE-120, T1190, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 9, 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=< V1.15(ACCC.3)C0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zyxel Networks · NR7101 Firmwareversion=< V1.15(ACCC.3)C0

Published CVSS scores

8.6ZyxelCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1190Exploit Public-Facing Application
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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