Zyxel security advisory for local privilege escalation and authenticated directory traversal vulnerabilities of firewalls

CVE: CVE-2022-30526, CVE-2022-2030



Zyxel has released patches for products affected by local privilege escalation and authenticated directory traversal vulnerabilities. Users are advised to install them for optimal protection.


What is the vulnerability?


A privilege escalation vulnerability was identified in the CLI command of some firewall versions that could allow a local attacker to execute some OS commands with root privileges in some directories on a vulnerable device.


An authenticated directory traversal vulnerability caused by specific character sequences within an improperly sanitized URL was identified in some CGI programs of some firewall versions.


What versions are vulnerable—and what should you do?

After a thorough investigation, we’ve identified the vulnerable products for CVE-2022-30526 and CVE-2022-2030 that are within their vulnerability support period, with their firmware patches shown in the table below.

Affected model Affected version Patch availability
CVE-2022-30526 CVE-2022-2030
USG FLEX 100(W), 200, 500, 700 ZLD V4.50~V5.30 ZLD V4.50~V5.30 ZLD V5.31
USG FLEX 50(W) / USG20(W)-VPN ZLD V4.16~V5.30 ZLD V4.20~V5.30 ZLD V5.31
ATP series ZLD V4.32~V5.30 ZLD V4.32~V5.30 ZLD V5.31
VPN Series ZLD V4.30~V5.30 ZLD V4.30~V5.30 ZLD V5.31
USG/ZyWALL ZLD V4.09~V4.72 ZLD V4.20~V4.72 ZLD V4.72 week28

Got a question?

Please contact your local service rep or visit Zyxel’s forum for further information or assistance.



Thanks to the following security consultancies for reporting the issues to us:

  • Rapid7 for CVE-2022-30526
  • Maurizio Agazzini (HN Security) in collaboration with SSD Secure Disclosure for CVE-2022-2030


Revision history

2022-07-19: Initial release
2022-07-28: Updated the affected version of USG FLEX 50(W) / USG20(W)-VPN and USG/ZyWALL and added the patch download link for USG/ZyWALL