CVE-2022-30525

KEVZyxel Multiple Firewalls OS Command Injection Vulnerability

Description

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

A OS command injection vulnerability in the CGI program of Zyxel USG FLEX 100(W) firmware versions 5.00 through 5.21 Patch 1, USG FLEX 200 firmware versions 5.00 through 5.21 Patch 1, USG FLEX 500 firmware versions 5.00 through 5.21 Patch 1, USG FLEX 700 firmware versions 5.00 through 5.21 Patch 1, USG FLEX 50(W) firmware versions 5.10 through 5.21 Patch 1, USG20(W)-VPN firmware versions 5.10 through 5.21 Patch 1, ATP series firmware versions 5.10 through 5.21 Patch 1, VPN series firmware versions 4.60 through 5.21 Patch 1, which could allow an attacker to modify specific files and then execute some OS commands on a vulnerable device.

CVSS 3.1 vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

PublishedMay 12, 2022

Last modifiedJun 17, 2026

Added to KEVMay 16, 2022

Remediation dueJun 6, 2022

References

packetstormsecurity.com/files/167176/Zyxel-Remote-Command-Execution.htmlThird Party AdvisoryVDB Entry
packetstormsecurity.com/files/167182/Zyxel-Firewall-ZTP-Unauthenticated-Command-Injection.htmlExploitThird Party Advisory
packetstormsecurity.com/files/167372/Zyxel-USG-FLEX-5.21-Command-Injection.htmlExploitThird Party Advisory
packetstormsecurity.com/files/168202/Zyxel-Firewall-SUID-Binary-Privilege-Escalation.htmlExploitThird Party Advisory
zyxel.com/support/Zyxel-security-advisory-for-OS-command-injection-vulnerability-of-firewalls.shtmlVendor Advisory
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-30525US Government Resource

0 recent articles mention this CVE

Risk assessment · Critical

Actively exploited. Patch immediately.

Exploitation: Confirmed in the wild (CISA KEV)
Federal remediation deadline: Overdue by 1603 days
CVSS: 9.8 CRITICAL
EPSS (30-day exploit probability): 99.9% · top 1% of all CVEs
Weakness: CWE-78
Attack vector: Network, remotely reachable
Preconditions: No privileges and no user interaction

Recommended actions

1.Apply updates per vendor instructions.
2.Treat as emergency change: patch or isolate internet-facing instances first.
3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.

Assessment is derived automatically from the live signals above; verify against your own asset inventory.