CVE intelligence and bounded remediation

CVE-2022-0910 — Zyxel Vpn100 Firmware security vulnerability

Medium CVSS 6.5

A downgrade from two-factor authentication to one-factor authentication vulnerability in the CGI program of Zyxel USG/ZyWALL series firmware versions 4.32 through 4.71, USG FLEX series firmware versions 4.50 through 5.21, ATP series firmware versions 4.32 through 5.21, and VPN series firmware versions 4.32 through 5.21, that could allow an authenticated attacker to bypass the second authentication phase to connect the IPsec VPN server even though the two-factor authentication (2FA) was enabled.

Severity
Medium
CVSS
6.5 (3.1)
Published
2022-05-24
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-287

Affected products

  • zyxel / vpn100_firmware
  • zyxel / vpn1000_firmware
  • zyxel / vpn300_firmware
  • zyxel / vpn50_firmware
  • zyxel / atp100_firmware
  • zyxel / atp100w_firmware

Showing 6 representative product identities from 32 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authentication bypass and missing authentication

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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