Vulnerability identifier: #VU63569

Vulnerability risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-0910

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
USG series
Client/Desktop applications / Antivirus software/Personal firewalls
USG FLEX series
Client/Desktop applications / Antivirus software/Personal firewalls
VPN series
Client/Desktop applications / Antivirus software/Personal firewalls
ZyWALL
Other software / Other software solutions
ATP series
Hardware solutions / Routers for home users

Vendor: ZyXEL Communications Corp.

Description

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions in the CGI program. A remote attacker can downgrade from two-factor authentication to one-factor authentication via an IPsec VPN client.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

USG series: 4.32 - 4.71

ZyWALL: 4.32 - 4.71

USG FLEX series: 4.50 - 5.21

ATP series: 4.32 - 5.21

VPN series: 4.32 - 5.21

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External links
http://www.zyxel.com/support/multiple-vulnerabilities-of-firewalls-AP-controllers-and-APs.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.