CVE-2022-43391Network attack vector

Authenticated service interruption via unchecked CGI parameter

Published Jan 11, 2023 · Updated Oct 15, 2024

Buffer overflow in the CGI program of Zyxel NR7101 Firmware before 1.15(ACCC.3)C0 allows remote authenticated users to interrupt service. A CGI parameter is copied into a fixed-size buffer without an input-length check; Zyxel has not disclosed the parameter or handler. A crafted HTTP request reaches the flaw after authentication; WAN administration is disabled by default on most affected devices.

CVSS severity6.5
Medium
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in the CGI program of Zyxel NR7101 Firmware before 1.15(ACCC.3)C0 allows remote authenticated users to interrupt service. A CGI parameter is copied into a fixed-size buffer without an input-length check; Zyxel has not disclosed the parameter or handler. A crafted HTTP request reaches the flaw after authentication; WAN administration is disabled by default on most affected devices.

The record

CVE
CVE-2022-43391
Published
Jan 11, 2023
Updated
Oct 15, 2024
Vendor
Zyxel Networks
Product
NR7101 Firmware
Classifications
CWE-120, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 15, 2024Record 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 privilegesauthenticated

What is affected?

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

Published CVSS scores

6.5Zyxel CorporationCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1499.004Application or System Exploitation

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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