Multiple vulnerabilities in Zyxel firewalls

Published: 2023-05-25 | Updated: 2023-06-02

Risk	High
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2023-33009 CVE-2023-33010
CWE-ID	CWE-119
Exploitation vector	Network
Public exploit	Vulnerability #1 is being exploited in the wild. Vulnerability #2 is being exploited in the wild.
Vulnerable software Subscribe	ATP series Hardware solutions / Routers for home users USG FLEX series Client/Desktop applications / Antivirus software/Personal firewalls VPN series Client/Desktop applications / Antivirus software/Personal firewalls USG series Client/Desktop applications / Antivirus software/Personal firewalls USG FLEX 50W Hardware solutions / Firmware USG20W-VPN Hardware solutions / Firmware ZyWALL Other software / Other software solutions
Vendor	ZyXEL Communications Corp.

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Buffer overflow

EUVDB-ID: #VU76514

Risk: High

CVSSv3.1: 9.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2023-33009

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in the notification function. A remote attacker can trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

ATP series: 4.32 - 5.36 Patch 1

USG FLEX series: 4.50 - 5.36 Patch 1

USG FLEX 50W: 4.25 - 5.36 Patch 1

USG20W-VPN: 4.25 - 5.36 Patch 1

VPN series: 4.30 - 5.36 Patch 1

ZyWALL: 4.25 - 4.73 Patch 1

USG series: 4.25 - 4.73 Patch 1

External links

http://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-buffer-overflow-vulnerabilities-of-firewalls
http://www.zyxel.com/global/en/support/security-advisories/zyxels-guidance-for-the-recent-attacks-on-the-zywall-devices

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

2) Buffer overflow

EUVDB-ID: #VU76515