QID 730491

Date Published: 2022-05-16

QID 730491: Zyxel Firewall OS Command Injection Vulnerability

Zyxel Communications Corp. is a manufacturer of DSL and other networking devices.

A command injection vulnerability in the CGI program of some firewall versions could allow an attacker to modify specific files and then execute some OS commands on a vulnerable device.

Affected Versions:
ATP series running firmware: ZLD V5.00 through ZLD V5.21 Patch 1
VPN series running firmware: ZLD V4.60 through ZLD V5.21 Patch 1
USG FLEX 100(W), 200, 500, 700: ZLD V5.00 through ZLD V5.21 Patch 1
USG FLEX 50(W) / USG20(W)-VPN: ZLD V5.10 through ZLD V5.21 Patch 1

QID Detection Logic:(Unauthenticated)
This QID checks for vulnerable Zyxel Firewall by sending a crafted payload to ztp/cgi-bin/handler.

This allows an attacker to modify specific files and then execute some OS commands on a vulnerable device.

  • CVSS V3 rated as Critical - 9.8 severity.
  • CVSS V2 rated as Critical - 10 severity.
  • Solution
    Customer are advised to update the device firmware
    For more details please refer to advisory here.

    CVEs related to QID 730491

    Software Advisories
    Advisory ID Software Component Link
    CVE-2022-30525 URL Logo www.zyxel.com/support/Zyxel-security-advisory-for-OS-command-injection-vulnerability-of-firewalls.shtml
    © CVE.report 2026 |

    Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

    CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

    Free CVE JSON API cve.report/api

    CVE.report and Source URL Uptime Status status.cve.report