#VU59130 Insufficient Session Expiration in NBG6604 - CVE-2021-35034

Vulnerability identifier: #VU59130

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-35034

CWE-ID: CWE-613

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
NBG6604
Hardware solutions / Firmware

Vendor: ZyXEL Communications Corp.

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to insufficient session expiration issue in the CGI program. A remote non-authenticated attacker can obtain or guess session token and gain unauthorized access to session that belongs to another user.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

NBG6604: before 1.00(ABIR.9)C0

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

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.