Zyxel Multiple Firewalls OS Command Injection Vulnerability
Exploited since 2022-05-16. No WAF vendor names it yet. Our CRS test: blocked.
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
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.
Edge coverage
Claimed by vendorsAsk Vigil
AI · answers from this pageWorkers AI (Llama 3.3). Can be wrong: check the cited source.
Severity, decoded
CVSS 3.1Exploitable over the network, with no privileges and no user interaction, leading to full loss of confidentiality, integrity and availability.
How the score is built
- Attack vectorAn attacker can reach it over the internet; no access to your network needed.Network
- Attack complexityNo special conditions are needed; the attack works reliably.Low
- Privileges requiredNo account or login is needed.None
- User interactionNo one has to click or open anything; the attack works on its own.None
- ScopeThe damage stays within the vulnerable component.Unchanged
- Confidentiality impactAn attacker can read all data the affected component holds, or the most sensitive parts of it.High
- Integrity impactAn attacker can change any data or files the affected component protects.High
- Availability impactAn attacker can take the component down completely or keep it from serving anyone.High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAttackers are exploiting this in the wild.
Attackers can script the attack end to end and hit many targets at once.
A successful attack gives full control over the affected software or all of its data.
Public exploits
3 found- MetasploitZyxel Firewall ZTP Unauthenticated Command Injection2022-04-28 · exploit · rank Excellent · has check
- Exploit-DBZyxel USG FLEX 5.21 - OS Command Injection2022-06-03 · remote · hardware
- NucleiCVE-2022-30525.yamldetection template, replayed in our lab
Links are to third-party code: never run it outside an isolated lab.
Timeline
- 2022-04-28Metasploit module publishedZyxel Firewall ZTP Unauthenticated Command Injection
- 2022-05-12CVE publishedCVE List
- 2022-05-16Added to CISA KEVConfirmed exploitation in the wild
- 2022-06-03Exploit published on Exploit-DBZyxel USG FLEX 5.21 - OS Command Injection
- 2026-11-02Our test: OWASP Core Rule Set blocked itparanoia level 1, anomaly threshold 5, default CRS settings
- 2026-11-02Our test: OWASP Core Rule Set blocked itparanoia level 2, anomaly threshold 5, default CRS settings
Vendor statements
QuotedCloudflareWAF Managed Rules
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
AWSAWS WAF Managed Rules
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. AWS often describes a vulnerability without naming its CVE (for example "Log4j"). We count only entries that name the CVE, so AWS coverage is understated.
Microsoft AzureFront Door and Application Gateway WAF (DRS)
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. The rule tables name CVEs but carry no dates, so Azure is left out of every time-to-rule figure.
Google CloudCloud Armor preconfigured WAF rules
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
FastlyNext-Gen WAF virtual patches
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
F5Attack signatures (Distributed Cloud WAF)
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
AkamaiApp & API Protector (Adaptive Security Engine)
This vendor publishes no machine-readable rule changelog we can check.
OWASP CRSCore Rule Set (open source, used inside many WAFs)
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
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