CVE-2023-22918: Zyxel ATP100 Firmware

Medium severity, CVSS 6.5. EPSS: 0.8% chance of exploitation in the next 30 days.

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.

Affected products

• Zyxel ATP100 Firmware: from 4.32, before 5.36 (fixed in 5.36)
• Zyxel ATP100W Firmware: from 4.32, before 5.36 (fixed in 5.36)
• Zyxel ATP200 Firmware: from 4.32, before 5.36 (fixed in 5.36)
• Zyxel ATP500 Firmware: from 4.32, before 5.36 (fixed in 5.36)
• Zyxel ATP700 Firmware: from 4.32, before 5.36 (fixed in 5.36)
• Zyxel ATP800 Firmware: from 4.32, before 5.36 (fixed in 5.36)
• Zyxel NAP203 Firmware: up to and including 6.28\(abfa.0\)
• Zyxel NAP303 Firmware: up to and including 6.28\(abex.0\)
• Zyxel NAP353 Firmware: up to and including 6.28\(abey.0\)
• Zyxel NWA110AX Firmware: up to and including 6.50\(abtg.2\)
• Zyxel NWA1123-Ac-Pro Firmware: up to and including 6.28\(abhd.0\)
• Zyxel NWA1123-Ac Hd Firmware: up to and including 6.25\(abin.9\)
• Zyxel NWA1123ACV3 Firmware: up to and including 6.50\(abvt.0\)
• Zyxel NWA210AX Firmware: up to and including 6.50\(abtd.2\)
• Zyxel NWA220AX-6e Firmware: up to and including 6.50\(acco.2\)
• Zyxel NWA50AX-Pro Firmware: up to and including 6.50\(acge.0\)
• Zyxel NWA50AX Firmware: up to and including 6.55\(acge.1\)
• Zyxel NWA5123-Ac Hd Firmware: up to and including 6.25\(abim.9\)
• Zyxel NWA55AXE Firmware: up to and including 6.29\(abzl.1\)
• Zyxel NWA90AX-Pro Firmware: up to and including 6.50\(acgf.0\)
• Zyxel NWA90AX Firmware: up to and including 6.29\(accv.1\)
• Zyxel USG20-VPN Firmware: from 4.30, before 5.36 (fixed in 5.36)
• Zyxel Usg 20w-VPN Firmware: from 4.16, before 5.36 (fixed in 5.36)
• Zyxel Usg Flex 100 Firmware: from 4.50, before 5.36 (fixed in 5.36)
• Zyxel Usg Flex 100w Firmware: from 4.50, before 5.36 (fixed in 5.36)
• and 26 more

Published 2023-04-24. Last modified 2026-06-17.