Authentication bypass in several Zyxel firewalls

1) Improper Authentication

EUVDB-ID: #VU61723

Risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2022-0342

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to missing authentication checks in the web interface. A remote attacker can bypass authentication process and obtain administrative access to the device.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

USG series: before 4.71

ZyWALL: before 4.71

USG FLEX series: before 5.21 Patch 1

VPN series: before 5.21

NSG series: before 1.33p4_WK11

ATP series: before 5.21 Patch 1

CPE2.3

• cpe:2.3:a:zyxel_communications_corp:usg_series:*:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:zywall:*:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:usg_flex_series:*:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:vpn_series:*:*:*:*:*:*:*:*
• cpe:2.3:h:zyxel_communications_corp:nsg_series:*:*:*:*:*:*:*:*
• cpe:2.3:h:zyxel_communications_corp:atp_series:*:*:*:*:*:*:*:*

External links

https://www.zyxel.com/support/Zyxel-security-advisory-for-authentication-bypass-vulnerability-of-firewalls.shtml

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.