CVE-2023-34138
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 · uneditedA command injection vulnerability in the hotspot management feature of the Zyxel ATP series firmware versions 4.60 through 5.36 Patch 2, USG FLEX series firmware versions 4.60 through 5.36 Patch 2, USG FLEX 50(W) series firmware versions 4.60 through 5.36 Patch 2, USG20(W)-VPN series firmware versions 4.60 through 5.36 Patch 2, and VPN series firmware versions 4.60 through 5.36 Patch 2, could allow an unauthenticated, LAN-based attacker to execute some OS commands on an affected device if the attacker could trick an authorized administrator to add their IP address to the list of trusted RADIUS clients in advance.
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 confidenceA command injection vulnerability exists in the hotspot management feature of multiple Zyxel security appliance series (ATP, USG FLEX, USG FLEX 50W, USG20W-VPN, VPN). An unauthenticated LAN-based attacker who tricks an administrator into adding their IP to the trusted RADIUS clients list can execute arbitrary OS commands on the affected device.
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>= 4.60, < 5.37>= 4.60, < 5.37>= 4.60, < 5.37>= 4.60, < 5.37>= 4.60, < 5.37>= 4.60, < 5.37>= 4.60, < 5.37>= 4.60, < 5.37CVSS 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
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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 checksWork through these to decide whether this CVE applies to you.
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Identify device model and firmware versionAccess the device admin console or use CLI command 'show system-info' to retrieve the exact model number and firmware version installed.Affected if Firmware version is 4.60 or higher but lower than 5.37, and the device is one of: USG20W-VPN, USG2200-VPN, USG Flex 100, USG Flex 100w, USG Flex 200, USG Flex 50, USG Flex 500, or USG Flex 50w.
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Verify hotspot management feature is enabledIn the web admin interface, navigate to Configuration > Hotspot > General or use CLI to check if the hotspot management feature is turned on.Affected if Hotspot management is enabled on the device.
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Review trusted RADIUS client configurationIn the web admin interface, go to Configuration > Hotspot > RADIUS Settings > RADIUS Client or use CLI 'show hotspot radius-client' to list all IP addresses configured as trusted RADIUS clients.Affected if There are RADIUS client entries with IP addresses that you do not recognize or that belong to untrusted networks.
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Check RADIUS server settings for suspicious configurationsIn the web admin interface, navigate to Configuration > Hotspot > RADIUS Settings and inspect the RADIUS server shared secret and authentication settings.Affected if The RADIUS configuration allows authentication from any source or contains unexpected shared secrets.
The device is affected if it runs firmware version 4.60 through 5.36 (inclusive), is one of the listed USG models, and has hotspot management enabled with untrusted or unauthorized IP addresses in the RADIUS client list.
Generated from the published advisory. Verify against your own configuration.
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.
dbcve · scoped5.37
Update Zyxel firmware to a version beyond 5.36 Patch 2. Additionally, review and audit the trusted RADIUS client list to ensure no unauthorized IPs are present, and implement network segmentation to limit LAN-based attack surface.
Firmware version 5.37 or later for USG FLEX series, USG FLEX 50(W), USG20(W)-VPN, and ATP series
- Download firmware version 5.37 or later from Zyxel's official support website (www.zyxel.com/support) for your specific device model
- Access the USG device web management interface or CLI
- Navigate to the firmware upgrade section (typically under System > Firmware or Maintenance > File Manager)
- Upload the downloaded firmware file (.bin) to the device
- Apply the firmware upgrade and allow the device to reboot
- After reboot, verify the firmware version has been updated successfully
- If the hotspot management feature was previously configured, verify the RADIUS client configuration is correct after upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation3.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-34138 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-34138 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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