dbcve.org
Usg Flex 100w FirmwareOperating system · Zyxel

CVE-2022-2030

MEDIUM · 6.5 CVSS v3.1 Published 2022-07-19
Fix available
A fix is available. Upgrade to after 5.30 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A directory traversal vulnerability caused by specific character sequences within an improperly sanitized URL was identified in some CGI programs of Zyxel USG FLEX 100(W) firmware versions 4.50 through 5.30, USG FLEX 200 firmware versions 4.50 through 5.30, USG FLEX 500 firmware versions 4.50 through 5.30, USG FLEX 700 firmware versions 4.50 through 5.30, USG FLEX 50(W) firmware versions 4.16 through 5.30, USG20(W)-VPN firmware versions 4.16 through 5.30, ATP series firmware versions 4.32 through 5.30, VPN series firmware versions 4.30 through 5.30, USG/ZyWALL series firmware versions 4.11 through 4.72, that could allow an authenticated attacker to access some restricted files on a vulnerable device.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A directory traversal vulnerability exists in CGI programs of multiple Zyxel USG FLEX, ATP, and VPN series firewall devices due to improper sanitization of specific character sequences in URLs. An authenticated attacker can exploit this by crafting malicious URLs with traversal sequences (e.g., ../) to access restricted files outside the intended web root directory.

MitigationApply vendor-supplied firmware updates (latest patches address this vulnerability). If immediate patching is not feasible, limit administrative interface access to trusted IP addresses and implement web application firewall rules to detect and block directory traversal patterns.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Usg Flex 100w FirmwareOperating system
Affected:>= 4.50, <= 5.30
Usg Flex 200 FirmwareOperating system
Affected:>= 4.50, <= 5.30
Usg Flex 500 FirmwareOperating system
Affected:>= 4.50, <= 5.30
Usg Flex 700 FirmwareOperating system
Affected:>= 4.50, <= 5.30
Usg Flex 50w FirmwareOperating system
Affected:>= 4.20, <= 5.30
Usg20w Vpn FirmwareOperating system
Affected:>= 4.20, <= 5.30
Atp800 FirmwareOperating system
Affected:>= 4.32, <= 5.30
Atp700 FirmwareOperating system
Affected:>= 4.32, <= 5.30

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Zyxel device model
    Access the device web interface (usually via https://<device-ip>/) and check the dashboard or status page for the model name, or use CLI command 'show system-info' or 'sysinfo' to retrieve model information
    Affected if The device is not one of the following: USG Flex 100w, USG Flex 200, USG Flex 500, USG Flex 700, USG Flex 50w, USG20w VPN, ATP800, or ATP700
  2. Retrieve the current firmware version
    In the web interface, navigate to Maintenance > Firmware or Status > Device Info to view the firmware version. In CLI, use 'show system-info' or 'fwver' command
    Affected if Unable to retrieve firmware version or version is unknown
  3. Compare firmware version against affected ranges
    Check if the installed firmware version falls within any of these ranges: USG Flex 100w/200/500/700: 4.50 to 5.30; USG Flex 50w/USG20w VPN: 4.20 to 5.30; ATP800/ATP700: 4.32 to 5.30
    Affected if The firmware version is within any of the listed ranges (>=4.50 and <=5.30 for 100w/200/500/700; >=4.20 and <=5.30 for 50w/USG20w; >=4.32 and <=5.30 for ATP700/ATP800)
  4. Confirm web interface and CGI programs are enabled
    Verify the device web interface is accessible by navigating to https://<device-ip>/ in a browser. The vulnerability exists in CGI programs, so ensure the HTTP/HTTPS service is running. In CLI, use 'show service' to confirm web services are enabled
    Affected if The web interface (HTTP/HTTPS) is disabled or not accessible

The device is affected if it is one of the listed models (USG Flex 100w/200/500/700/50w, USG20w VPN, ATP700, ATP800) AND its firmware version falls within the specified vulnerable ranges AND the web interface is accessible.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 5.30
Interim mitigation

Apply vendor-supplied firmware updates (latest patches address this vulnerability). If immediate patching is not feasible, limit administrative interface access to trusted IP addresses and implement web application firewall rules to detect and block directory traversal patterns.

Fix this in Usg Flex 100w Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-2030 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data