CVE-2022-0342: An authentication bypass vulnerability in the CGI program of Zyxel USG/ZyWALL series firmware versions 4.20 through 4…
- Is it exploited?
Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of .
VulnCheck KEV lists it since . VulnCheck's own honeypots also recorded exploitation attempts.
- How likely is exploitation in the next 30 days?
- 95.1%
EPSS score, percentile 99.9 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 9.8 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 4.20 through 4.70
- 4.50 through 5.20
- 4.32 through 5.20
- 4.30 through 5.20
- 1.20 through 1.33 Patch 4
Source: CISA KEV 2026.10.29, as of ; VulnCheck KEV, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
Description
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.
Source: CVE List, as of . About the data.
What to do
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
Versions by product, as listed in the CVE record (5 products)
| Status | Versions |
|---|---|
| Affected | 4.20 through 4.70 |
| Status | Versions |
|---|---|
| Affected | 4.50 through 5.20 |
| Status | Versions |
|---|---|
| Affected | 4.32 through 5.20 |
| Status | Versions |
|---|---|
| Affected | 4.30 through 5.20 |
| Status | Versions |
|---|---|
| Affected | 1.20 through 1.33 Patch 4 |
Source: CVE List, as of . About the data.
Weakness
CWE-287
- CWE-287: Improper Authentication
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
References
1
Known exploited Zyxel vulnerabilities
- CVE-2026-7273: Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability
- CVE-2024-40890: Zyxel DSL CPE OS Command Injection Vulnerability
- CVE-2024-40891: Zyxel DSL CPE OS Command Injection Vulnerability
- CVE-2024-11667: Zyxel Multiple Firewalls Path Traversal Vulnerability
- CVE-2017-6884: Zyxel EMG2926 Routers Command Injection Vulnerability