CVE-2022-30525Known exploitationPublic exploitNetwork attack vector

Unauthenticated command execution via unsanitized WAN parameters

Published May 12, 2022 · Updated Oct 21, 2025

OS command injection in Zyxel firewall firmware through 5.21 Patch 1 allows remote attackers to execute commands without authentication. The /ztp/cgi-bin/handler setWanPortSt path passes unsanitized mtu or data values to os.system in lib_wan_settings.py. The administrative HTTP interface must be network reachable; injected commands run as nobody and can modify specific files on the appliance.

CVSS severity9.8
Critical
EPSS probability99.94%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Zyxel firewall firmware through 5.21 Patch 1 allows remote attackers to execute commands without authentication. The /ztp/cgi-bin/handler setWanPortSt path passes unsanitized mtu or data values to os.system in lib_wan_settings.py. The administrative HTTP interface must be network reachable; injected commands run as nobody and can modify specific files on the appliance.

The record

CVE
CVE-2022-30525
Published
May 12, 2022
Updated
Oct 21, 2025
Vendor
Zyxel Networks
Product
Zyxel USG FLEX 50W Firmware
Classifications
CWE-78, T1190, T1059.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 12, 2022CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=5.10 through 5.21 Patch 1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zyxel Networks · Zyxel USG FLEX 50W Firmwareversion=5.10 through 5.21 Patch 1
Zyxel Networks · Zyxel USG FLEX 100W Firmwareversion=5.00 through 5.21 Patch 1
Zyxel Networks · Zyxel ATP Series Firmwareversion=5.10 through 5.21 Patch 1
Zyxel Networks · Zyxel USG20(W)-VPN Series Firmwareversion=5.10 through 5.21 Patch 1
Zyxel Networks · Zyxel USG FLEX 500 Firmwareversion=5.00 through 5.21 Patch 1
Zyxel Networks · Zyxel VPN Series Firmwareversion=4.60 through 5.21 Patch 1
Zyxel Networks · Zyxel USG FLEX 200 Firmwareversion=5.00 through 5.21 Patch 1
Zyxel Networks · USG FLEX 700 Firmwareversion=5.00 through 5.21 Patch 1

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.

Daily unique IPsShadowserver observations through Sep 15, 2026. Gaps indicate unavailable data.
Sep 9, 2026Sep 15, 2026
View daily counts
Reporting dayUnique IPs
Sep 9, 2026Unavailable
Sep 10, 2026Unavailable
Sep 11, 2026Unavailable
Sep 12, 2026Unavailable
Sep 13, 2026Unavailable
Sep 14, 20262
Sep 15, 2026Unavailable
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1190Exploit Public-Facing Application
T1059.004Unix Shell

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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