CVE-2024-29972Public exploitNetwork attack vector

Root SSH access via unauthenticated CGI handler

Published Jun 4, 2024 · Updated Aug 2, 2024

OS command injection in Zyxel NAS326 and NAS542 firmware allows remote attackers to enable root SSH access via an unauthenticated HTTP request. The SUID remote_help-cgi program maps an attacker-controlled type value to a handler that restarts SSH, opens WAN port 22, and rewrites the password for a root-privileged support account. A permitted path substring bypasses authentication; affected versions are NAS326 before 5.21(AAZF.17)C0 and NAS542 before 5.21(ABAG.14)C0.

CVSS severity9.8
Critical
EPSS probability89.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Zyxel NAS326 and NAS542 firmware allows remote attackers to enable root SSH access via an unauthenticated HTTP request. The SUID remote_help-cgi program maps an attacker-controlled type value to a handler that restarts SSH, opens WAN port 22, and rewrites the password for a root-privileged support account. A permitted path substring bypasses authentication; affected versions are NAS326 before 5.21(AAZF.17)C0 and NAS542 before 5.21(ABAG.14)C0.

The record

CVE
CVE-2024-29972
Published
Jun 4, 2024
Updated
Aug 2, 2024
Vendor
Zyxel Networks
Product
NAS542 Firmware
Classifications
CWE-78, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 4, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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=0 <5.21\(abag.14\)co
  2. Affected versionversion=< V5.21(ABAG.14)C0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zyxel Networks · NAS542 Firmwareversion=0 <5.21\(abag.14\)co; version=< V5.21(ABAG.14)C0
Zyxel Networks · NAS326 Firmwareversion=0 <v5.21\(aazf.17\)co; version=< V5.21(AAZF.17)C0

Published CVSS scores

9.8Zyxel CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.

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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 exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1190Exploit Public-Facing Application

Public exploit references

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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