Cyber Resilience

CVE-2022-30525

RCE in Zyxel Usg Flex 100W Firmware 5.00 – 5.30

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRCECommand Injection
Published
12 May 2022
Modified
27 October 2025
KEV Added
16 May 2022
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.99 100.0th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2022-30525 is a critical-severity OS Command Injection (CWE-78) vulnerability in Zyxel Usg Flex 100W Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 0.0% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2022-30525 is an OS command injection vulnerability (CWE-78) residing in the CGI program of multiple Zyxel firewall product lines. Affected devices include USG FLEX 100(W), 200, 500, and 700 running firmware 5.00–5.21 Patch 1; USG FLEX 50(W) and USG20(W)-VPN running 5.10–5.21 Patch 1; ATP series running 5.10–5.21 Patch 1; and VPN series running 4.60–5.21 Patch 1. The flaw permits an attacker to modify specific files and subsequently execute arbitrary operating-system commands on the device.

Unauthenticated remote attackers can exploit the issue over the network without user interaction. Successful exploitation yields full control of the affected appliance, enabling arbitrary command execution with impacts to confidentiality, integrity, and availability, as reflected in the CVSS 9.8 base score.

Zyxel’s security advisory directs customers to apply the vendor-supplied firmware updates that remediate the command-injection flaw in the CGI component. Public exploit artifacts, including unauthenticated command-injection and remote-code-execution proofs, have been posted to Packet Storm.

The EPSS score reached a peak of 0.9756 and remains at 0.9445, indicating sustained exploitation interest after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
KEV Date Added
16 May 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-28771Same product: Zyxel Atp100both on KEV
CVE-2020-9054Same product: Zyxel Atp100both on KEV
CVE-2023-27991Same product: Zyxel Atp100
CVE-2024-40890Same vendor: Zyxelboth on KEV
CVE-2024-40891Same vendor: Zyxelboth on KEV
CVE-2023-27992Same vendor: Zyxelboth on KEV
CVE-2017-6884Same vendor: Zyxelboth on KEV
CVE-2024-7203Same product: Zyxel Atp100
CVE-2024-42057Same product: Zyxel Atp100
CVE-2024-42060Same product: Zyxel Atp100

Affected Assets

zyxel
usg flex 100w firmware
5.00 — 5.30
zyxel
usg flex 200 firmware
5.00 — 5.30
zyxel
usg flex 500 firmware
5.00 — 5.30
zyxel
usg flex 700 firmware
5.00 — 5.30
zyxel
vpn100 firmware
4.60 — 5.30
zyxel
vpn1000 firmware
4.60 — 5.30
zyxel
vpn300 firmware
4.60 — 5.30
zyxel
vpn50 firmware
4.60 — 5.30
zyxel
atp100 firmware
5.10 — 5.30
zyxel
atp100w firmware
5.10 — 5.30
+6 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References