Cyber Resilience

CVE-2022-0342

Critical

Published: 28 March 2022

Published
28 March 2022
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.9236 99.7th percentile
Risk Priority 75 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2022-0342 is a critical-severity Improper Authentication (CWE-287) vulnerability in Zyxel Nsg300 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 0.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis

An authentication bypass vulnerability tracked as CVE-2022-0342 affects the CGI program in multiple Zyxel firewall product lines. Impacted firmware includes USG/ZyWALL series versions 4.20 through 4.70, USG FLEX series 4.50 through 5.20, ATP series 4.32 through 5.20, VPN series 4.30 through 5.20, and NSG series V1.20 through V1.33 Patch 4. The flaw, assigned CWE-287 and carrying a CVSS v3.1 score of 9.8, permits an unauthenticated remote attacker to circumvent web authentication controls.

An attacker with network access can exploit the issue without credentials or user interaction to obtain full administrative access to the affected device. Successful exploitation grants the ability to read, modify, or delete configuration and data, fully compromising confidentiality, integrity, and availability of the firewall.

Zyxel published a security advisory detailing the vulnerability and directing customers to apply available firmware updates or configuration mitigations for the listed product families.

The associated EPSS score remains elevated, with a current value of 0.9236 and a peak of 0.9256, indicating sustained exploitation interest following disclosure.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

zyxel
usg40 firmware
4.20 — 4.71
zyxel
usg40w firmware
4.20 — 4.71
zyxel
usg60 firmware
4.20 — 4.71
zyxel
usg60w firmware
4.20 — 4.71
zyxel
zywall 110 firmware
4.20 — 4.71
zyxel
zywall 310 firmware
4.20 — 4.71
zyxel
zywall 1100 firmware
4.20 — 4.71
zyxel
usg flex 100 firmware
4.50 — 5.20
zyxel
usg flex 200 firmware
4.50 — 5.20
zyxel
usg flex 500 firmware
4.50 — 5.20
+13 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-287

Detects unauthorized successful logons resulting from improper authentication implementations.

addresses: CWE-287

Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.

addresses: CWE-287

Security awareness training instructs users on secure authentication practices and avoiding credential compromise.

addresses: CWE-287

Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.

addresses: CWE-287

Non-repudiation requires strong authentication mechanisms to irrefutably attribute performed actions to specific individuals or processes.

addresses: CWE-287

Session content review can reveal authentication bypasses or failures in session establishment.

addresses: CWE-287

Review of authentication-related audit records can detect improper authentication mechanisms or bypasses.

addresses: CWE-287

Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.

References