CVE-2023-22918

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-04-24 · updated 2026-06-17
Weakness: CWE-359

Description

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: through 6.28\(abfa.0\)
Zyxel Nap303 Firmware: through 6.28\(abex.0\)
Zyxel Nap353 Firmware: through 6.28\(abey.0\)
Zyxel NWA110AX firmware: through 6.50\(abtg.2\)
Zyxel Nwa1123-Ac-Pro Firmware: through 6.28\(abhd.0\)
Zyxel Nwa1123-Ac Hd Firmware: through 6.25\(abin.9\)
Zyxel NWA1123ACv3 firmware: through 6.50\(abvt.0\)
Zyxel Nwa210Ax Firmware: through 6.50\(abtd.2\)
Zyxel Nwa220Ax-6E Firmware: through 6.50\(acco.2\)
Zyxel Nwa50Ax-Pro Firmware: through 6.50\(acge.0\)
Zyxel NWA50AX firmware: through 6.55\(acge.1\)
Zyxel Nwa5123-Ac Hd Firmware: through 6.25\(abim.9\)
Zyxel Nwa55Axe Firmware: through 6.29\(abzl.1\)
Zyxel Nwa90Ax-Pro Firmware: through 6.50\(acgf.0\)
Zyxel Nwa90Ax Firmware: through 6.29\(accv.1\)
Zyxel Usg20-Vpn Firmware: from 4.30 before 5.36 — fixed in 5.36
Zyxel USG 20(W)-VPN firmware: from 4.16 before 5.36 — fixed in 5.36
Zyxel firewall (ZLD): from 4.50 before 5.36 — fixed in 5.36
Zyxel USG FLEX 100(W) firmware: from 4.50 before 5.36 — fixed in 5.36
Zyxel USG FLEX 200 firmware: from 4.50 before 5.36 — fixed in 5.36
Zyxel USG FLEX 500 firmware: from 4.50 before 5.36 — fixed in 5.36
Zyxel Usg Flex 50 Firmware: from 4.50 before 5.36 — fixed in 5.36
Zyxel USG FLEX 50(W) firmware: from 4.16 before 5.36 — fixed in 5.36
Zyxel USG FLEX 700 firmware: from 4.50 before 5.36 — fixed in 5.36

How to fix

Upgrade to a fixed version: Zyxel Atp100 Firmware 5.36; Zyxel Atp100W Firmware 5.36; Zyxel Atp200 Firmware 5.36; Zyxel Atp500 Firmware 5.36; Zyxel Atp700 Firmware 5.36; Zyxel Atp800 Firmware 5.36; Zyxel Usg20-Vpn Firmware 5.36; Zyxel USG 20(W)-VPN firmware 5.36; Zyxel firewall (ZLD) 5.36; Zyxel USG FLEX 100(W) firmware 5.36; Zyxel USG FLEX 200 firmware 5.36; Zyxel USG FLEX 500 firmware 5.36. Check the vendor advisory for mitigations.

References

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