CVE-2022-0342

Home/CVE/An authentication bypass vulnerability in the CGI program of Zyxel USG/ZyWALL series firmware versions 4.20 through 4.70

CVE

An authentication bypass vulnerability in the CGI program of Zyxel USG/ZyWALL series firmware versions 4.20 through 4.70

An authentication bypass vulnerability in the CGI program of Zyxel USG/ZyWALL series firmware versions 4.20 through 4.70, USG FLEX series firmware versions 4.50 through 5.20, ATP series firmware versions 4.32 through 5.20, VPN series firmware versions 4.30 through 5.20, and NSG series firmware versions V1.20 through V1.33 Patch 4, which could allow an attacker to bypass the web authentication and obtain administrative access of the device.

CRITICAL · CVSS 9.8 EPSS 0.92364

Act now

EPSS ≥ 0.50 - high probability of exploitation in the next 30 days
EPSS percentile: top 0% of all CVEs by exploitation likelihood
Public exploit or PoC is available
CVSS base score ≥ 7.0

Sigma rules0 YARA rules0

⬡

Weakness Classification

CWE-287Improper Authentication

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Affected Products & Versions

zyxel usg40 firmware>= 4.20 and < 4.71
zyxel usg40w firmware>= 4.20 and < 4.71
zyxel usg60 firmware>= 4.20 and < 4.71
zyxel usg60w firmware>= 4.20 and < 4.71
zyxel zywall 110 firmware>= 4.20 and < 4.71
zyxel zywall 310 firmware>= 4.20 and < 4.71
zyxel zywall 1100 firmware>= 4.20 and < 4.71
zyxel usg flex 100 firmware>= 4.50 and <= 5.20
Show all 24 affected productszyxel usg flex 200 firmware>= 4.50 and <= 5.20
zyxel usg flex 500 firmware>= 4.50 and <= 5.20
zyxel usg flex 100w firmware>= 4.50 and <= 5.20
zyxel usg flex 700 firmware>= 4.50 and <= 5.20
zyxel atp100 firmware>= 4.32 and <= 5.20
zyxel atp100w firmware>= 4.32 and <= 5.20
zyxel atp200 firmware>= 4.32 and <= 5.20
zyxel atp500 firmware>= 4.32 and <= 5.20
zyxel atp700 firmware>= 4.32 and <= 5.20
zyxel atp800 firmware>= 4.32 and <= 5.20
zyxel vpn50 firmware>= 4.30 and < 5.21
zyxel vpn100 firmware>= 4.30 and < 5.21
zyxel vpn300 firmware>= 4.30 and < 5.21
zyxel vpn1000 firmware>= 4.30 and < 5.21
zyxel nsg300 firmware>= 1.20 and < 1.33
zyxel nsg300 firmwareall versions

⚠

Public Exploits & PoCs

nucleiZyxel - Authentication Bypasscritical

◈

Detection Rules (IDS/IPS)

et-openET WEB_SPECIFIC_APPS Zyxel USG/Zywall Authentication Bypass Attempt (CVE-2022-0342)attempted-admin

Open rulesets (ET Open, Snort Community, abuse.ch) link to source. Commercial rulesets are reference-only.

▣

Scoring & Timeline

9.8

CRITICAL · CVSS v3.1 · security@zyxel.com.tw

View on NVD

Attack Vector

Network Adjacent Local Physical

Attack Complexity

Low High

Privileges Required

None Low High

User Interaction

None Required

Scope

Unchanged Changed

Confidentiality

None Low High

Integrity

None Low High

Availability

None Low High

Published to NVD28 Mar 2022 · 01:15 PM

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

🔗

References & Sources

Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.

https://www.zyxel.com/support/Zyxel-security-advisory-for-authentication-bypass-vulnerability-of-firewalls.shtmlVendor Advisory

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