TI-2021-14000 Aliases CVE-2021-35034 GHSA-38gc-w4h9-7pmf

Insufficient session expiration in Zyxel NBG6604 series firmware

MEDIUM 41CWE-613Published 2021-12-29 · Updated 2024-08-04

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Security bypass
Confidentiality · integrity · availability: High · High · None
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-613.

Summary

An insufficient session expiration vulnerability in the CGI program of the Zyxel NBG6604 firmware could allow a remote attacker to access the device if the correct token can be intercepted.

Why it matters now

EPSS 0.01079 65th 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	NBG6604 series firmware	1.00(ABIR.8)C0	—	No fix listed	CNA

NBG6604 series firmware VendorZyxel Affected 1.00(ABIR.8)C0 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:o:zyxel:nbg6604_firmware::::::::	before 1.00\(abir.9\)c0	Vulnerable	Zyxel
cpe:2.3:h:zyxel:nbg6604:-:::::::*	not specified by NVD	Running on	Zyxel

cpe:2.3:o:zyxel:nbg6604_firmware:*:*:*:*:*:*:*:* Versions before 1.00\(abir.9\)c0 Vulnerable ·Zyxel
cpe:2.3:h:zyxel:nbg6604:-:*:*:*:*:*:*:* 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-2021-35034
2026-10-03 Alias added: GHSA-38gc-w4h9-7pmf

References

Advisory 1

https://www.zyxel.com/support/Zyxel_security_advisory_for_sensitive_information_vulnerabilities_of_NBG6604_home_router.shtml

TI-2023-16201 OS command injection in Zyxel NBG6604 firmware CVSS 3.1HIGH 8.8
TI-2023-09057 OS command injection in Zyxel NBG6604 firmware CVSS 3.1HIGH 8.8
TI-2021-14001 Cleartext storage of sensitive information in Zyxel NBG6604 series firmware CVSS 3.1MEDIUM 6.5

Sources

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