TI-2021-13994 Aliases CVE-2021-35028 GHSA-qfm3-mj8g-3hm7

OS command injection in Zyxel ZyWALL VPN2S Firmware

LOW 34CWE-78Published 2021-09-29 · Updated 2024-08-04

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Code execution
Confidentiality · integrity · availability: High · High · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-78.

Summary

A command injection vulnerability in the CGI program of the Zyxel VPN2S firmware version 1.12 could allow an authenticated, local user to execute arbitrary OS commands.

Why it matters now

EPSS 0.00305 23rd 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	ZyWALL VPN2S Firmware	1.12(ABLN.0)C0	—	No fix listed	CNA

ZyWALL VPN2S Firmware VendorZyxel Affected 1.12(ABLN.0)C0 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:o:zyxel:zywall_vpn2s_firmware:1.12\(abln.0\)c0:::::::*	1.12(abln.0)c0	Vulnerable	Zyxel
cpe:2.3:h:zyxel:zywall_vpn2s:-:::::::*	not specified by NVD	Running on	Zyxel

cpe:2.3:o:zyxel:zywall_vpn2s_firmware:1.12\(abln.0\)c0:*:*:*:*:*:*:* Versions 1.12(abln.0)c0 Vulnerable ·Zyxel
cpe:2.3:h:zyxel:zywall_vpn2s:-:*:*:*:*:*:*:* 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-2021-35028
2026-10-03 Alias added: GHSA-qfm3-mj8g-3hm7

References

Patch 1

https://www.zyxel.com/support/Zyxel_security_advisory_for_directory_traversal_and_command_injection_vulnerabilities_of_VPN2S_Firewall.shtml

TI-2023-16200 OS command injection in Zyxel ATP series firmware CVSS 3.1HIGH 8.8
TI-2023-16983 OS command injection in Zyxel USG FLEX series firmware CVSS 3.1HIGH 8.8
TI-2023-16199 A format string vulnerability in the Zyxel ATP series firmware versions 5.10 through 5.36… CVSS 3.1HIGH 8.8
TI-2023-13277 OS command injection in Zyxel ATP series firmware CVSS 3.1HIGH 8.8
TI-2023-16985 OS command injection in Zyxel ATP series firmware CVSS 3.1HIGH 8.0
TI-2023-16982 OS command injection in Zyxel ATP series firmware CVSS 3.1HIGH 8.0

See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences