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Atp200 FirmwareOperating system · Zyxel

CVE-2023-22918

MEDIUM · 6.5 CVSS v3.1 Published 2023-04-24
Fix available
A fix is available. Upgrade to 5.36 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click Patch available

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 post-authentication information exposure vulnerability in the CGI program of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, VPN series firmware versions 4.30 through 5.35, NWA110AX firmware version 6.50(ABTG.2) and earlier versions, WAC500 firmware version 6.50(ABVS.0) and earlier versions, and WAX510D firmware version 6.50(ABTF.2) and earlier versions, which could allow a remote authenticated attacker to retrieve encrypted information of the administrator on an affected 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

A detailed technical summary for this CVE is being prepared.

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
Atp200 FirmwareOperating system
Affected:>= 4.32, < 5.36
Atp100 FirmwareOperating system
Affected:>= 4.32, < 5.36
Atp700 FirmwareOperating system
Affected:>= 4.32, < 5.36
Atp500 FirmwareOperating system
Affected:>= 4.32, < 5.36
Atp100w FirmwareOperating system
Affected:>= 4.32, < 5.36
Atp800 FirmwareOperating system
Affected:>= 4.32, < 5.36
Usg Flex 100 FirmwareOperating system
Affected:>= 4.50, < 5.36
Usg Flex 50 FirmwareOperating system
Affected:>= 4.50, < 5.36

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

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 · scoped
Upgrade available Upgrade to 5.36 or later
Fixed in 5.36
Vendor patch www.zyxel.com →
Recommended fix High confidence

Zyxel ATP/USG FLEX firmware version 5.36 or later

  1. 1. Obtain the fixed firmware version 5.36 or later from Zyxel's official support portal at www.zyxel.com
  2. 2. Log into the Zyxel device management interface as an administrator
  3. 3. Navigate to the firmware upgrade section (typically under Maintenance > Firmware Upgrade)
  4. 4. Upload the downloaded firmware file (.bin) for your specific model (ATP200, ATP100, ATP700, ATP500, ATP100w, ATP800, USG Flex 100, or USG Flex 50)
  5. 5. Wait for the firmware upload to complete and the device to reboot automatically
  6. 6. After reboot, verify the firmware version has been updated to 5.36 or later by checking the device status page
  7. 7. Re-authenticate and confirm the CGI program vulnerability has been remediated by verifying the information exposure is no longer present
Caveat Review Zyxel release notes for version 5.36 for any configuration or feature changes before upgrading; ensure backup of current configuration is performed

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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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-2023-22918 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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