Improper authentication in Zyxel USG/ZyWALL series firmware
Priority CRITICAL 86CWE-287Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-287.
Summary
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.
Why it matters now
EPSS 0.95134 99th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Zyxel | USG/ZyWALL series firmware | 4.20 through 4.70 | — | No fix listed | CNA |
| Zyxel | USG FLEX series firmware | 4.50 through 5.20 | — | No fix listed | CNA |
| Zyxel | ATP series firmware | 4.32 through 5.20 | — | No fix listed | CNA |
| Zyxel | VPN series firmware | 4.30 through 5.20 | — | No fix listed | CNA |
| Zyxel | NSG series firmware | 1.20 through 1.33 Patch 4 | — | No fix listed | CNA |
- USG/ZyWALL series firmware VendorZyxel Affected 4.20 through 4.70 Fixed in — No fix listed CNA
- USG FLEX series firmware VendorZyxel Affected 4.50 through 5.20 Fixed in — No fix listed CNA
- ATP series firmware VendorZyxel Affected 4.32 through 5.20 Fixed in — No fix listed CNA
- VPN series firmware VendorZyxel Affected 4.30 through 5.20 Fixed in — No fix listed CNA
- NSG series firmware VendorZyxel Affected 1.20 through 1.33 Patch 4 Fixed in — No fix listed CNA
CPE configurations NVD · 48
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:zyxel:usg40_firmware:*:*:*:*:*:*:*:* | 4.20 to before 4.71 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:usg40:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:usg40w_firmware:*:*:*:*:*:*:*:* | 4.20 to before 4.71 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:usg40w:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:usg60_firmware:*:*:*:*:*:*:*:* | 4.20 to before 4.71 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:usg60:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:usg60w_firmware:*:*:*:*:*:*:*:* | 4.20 to before 4.71 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:usg60w:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:zywall_110_firmware:*:*:*:*:*:*:*:* | 4.20 to before 4.71 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:zywall_110:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
- cpe:2.3:o:zyxel:usg40_firmware:*:*:*:*:*:*:*:* Versions 4.20 to before 4.71 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:usg40:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:usg40w_firmware:*:*:*:*:*:*:*:* Versions 4.20 to before 4.71 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:usg40w:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:usg60_firmware:*:*:*:*:*:*:*:* Versions 4.20 to before 4.71 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:usg60:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:usg60w_firmware:*:*:*:*:*:*:*:* Versions 4.20 to before 4.71 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:usg60w:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:zywall_110_firmware:*:*:*:*:*:*:*:* Versions 4.20 to before 4.71 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:zywall_110:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
Show 38 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:zyxel:zywall_310_firmware:*:*:*:*:*:*:*:* | 4.20 to before 4.71 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:zywall_310:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:zywall_1100_firmware:*:*:*:*:*:*:*:* | 4.20 to before 4.71 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:zywall_1100:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:usg_flex_100_firmware:*:*:*:*:*:*:*:* | 4.50 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:usg_flex_100:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:usg_flex_200_firmware:*:*:*:*:*:*:*:* | 4.50 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:usg_flex_200:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:usg_flex_500_firmware:*:*:*:*:*:*:*:* | 4.50 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:usg_flex_500:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:usg_flex_100w_firmware:*:*:*:*:*:*:*:* | 4.50 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:usg_flex_100w:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:usg_flex_700_firmware:*:*:*:*:*:*:*:* | 4.50 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:usg_flex_700:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:atp100_firmware:*:*:*:*:*:*:*:* | 4.32 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:atp100:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:atp100w_firmware:*:*:*:*:*:*:*:* | 4.32 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:atp100w:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:atp200_firmware:*:*:*:*:*:*:*:* | 4.32 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:atp200:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:atp500_firmware:*:*:*:*:*:*:*:* | 4.32 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:atp500:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:atp700_firmware:*:*:*:*:*:*:*:* | 4.32 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:atp700:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:atp800_firmware:*:*:*:*:*:*:*:* | 4.32 – 5.20 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:atp800:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:vpn50_firmware:*:*:*:*:*:*:*:* | 4.30 to before 5.21 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:vpn50:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:vpn100_firmware:*:*:*:*:*:*:*:* | 4.30 to before 5.21 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:vpn100:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:vpn300_firmware:*:*:*:*:*:*:*:* | 4.30 to before 5.21 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:vpn300:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:vpn1000_firmware:*:*:*:*:*:*:*:* | 4.30 to before 5.21 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:vpn1000:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
| cpe:2.3:o:zyxel:nsg300_firmware:*:*:*:*:*:*:*:* | 1.20 to before 1.33 | Vulnerable | Zyxel |
| cpe:2.3:o:zyxel:nsg300_firmware:1.33:-:*:*:*:*:*:* | 1.33 | Vulnerable | Zyxel |
| cpe:2.3:o:zyxel:nsg300_firmware:1.33:p4:*:*:*:*:*:* | 1.33 p4 | Vulnerable | Zyxel |
| cpe:2.3:h:zyxel:nsg300:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Zyxel |
- cpe:2.3:o:zyxel:zywall_310_firmware:*:*:*:*:*:*:*:* Versions 4.20 to before 4.71 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:zywall_310:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:zywall_1100_firmware:*:*:*:*:*:*:*:* Versions 4.20 to before 4.71 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:zywall_1100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:usg_flex_100_firmware:*:*:*:*:*:*:*:* Versions 4.50 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:usg_flex_100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:usg_flex_200_firmware:*:*:*:*:*:*:*:* Versions 4.50 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:usg_flex_200:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:usg_flex_500_firmware:*:*:*:*:*:*:*:* Versions 4.50 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:usg_flex_500:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:usg_flex_100w_firmware:*:*:*:*:*:*:*:* Versions 4.50 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:usg_flex_100w:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:usg_flex_700_firmware:*:*:*:*:*:*:*:* Versions 4.50 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:usg_flex_700:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:atp100_firmware:*:*:*:*:*:*:*:* Versions 4.32 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:atp100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:atp100w_firmware:*:*:*:*:*:*:*:* Versions 4.32 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:atp100w:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:atp200_firmware:*:*:*:*:*:*:*:* Versions 4.32 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:atp200:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:atp500_firmware:*:*:*:*:*:*:*:* Versions 4.32 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:atp500:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:atp700_firmware:*:*:*:*:*:*:*:* Versions 4.32 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:atp700:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:atp800_firmware:*:*:*:*:*:*:*:* Versions 4.32 – 5.20 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:atp800:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:vpn50_firmware:*:*:*:*:*:*:*:* Versions 4.30 to before 5.21 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:vpn50:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:vpn100_firmware:*:*:*:*:*:*:*:* Versions 4.30 to before 5.21 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:vpn100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:vpn300_firmware:*:*:*:*:*:*:*:* Versions 4.30 to before 5.21 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:vpn300:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:vpn1000_firmware:*:*:*:*:*:*:*:* Versions 4.30 to before 5.21 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:vpn1000:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
- cpe:2.3:o:zyxel:nsg300_firmware:*:*:*:*:*:*:*:* Versions 1.20 to before 1.33 Vulnerable ·Zyxel
- cpe:2.3:o:zyxel:nsg300_firmware:1.33:-:*:*:*:*:*:* Versions 1.33 Vulnerable ·Zyxel
- cpe:2.3:o:zyxel:nsg300_firmware:1.33:p4:*:*:*:*:*:* Versions 1.33 p4 Vulnerable ·Zyxel
- cpe:2.3:h:zyxel:nsg300:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2022-0342
- 2026-10-03 Alias added: GHSA-5g3j-g6gx-xfcg
References
More Zyxel Atp100 Firmware vulnerabilities
- TI-2023-16198 Buffer overflow in Zyxel ATP series firmware KEVCVSS 3.1CRITICAL 9.8
- TI-2023-16197 Buffer overflow in Zyxel ATP series firmware KEVCVSS 3.1CRITICAL 9.8
- TI-2023-13281 OS command injection in Zyxel ZyWALL/USG series firmware KEVCVSS 3.1CRITICAL 9.8
- TI-2022-12682 OS command injection in Zyxel USG FLEX 100 firmware KEVCVSS 3.1CRITICAL 9.8
- TI-2020-17772 Firmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with… KEVCVSS 3.1CRITICAL 9.8
- TI-2020-07267 OS command injection in Zyxel NAS326 KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2022-0342 · CVE Program
- CVE-2022-0342 · NVD
- FIRST EPSS
- GHSA-5g3j-g6gx-xfcg · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences