Buffer overflow in ZyXEL Communications Corp. products - CVE-2023-33009

Vulnerability identifier: #VU76514

CSH Severity: High

CVSS v4: 9.3 [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]

CVE-ID: CVE-2023-33009

CWE-ID: CWE-119

Exploitation vector: Remote access

Exploit availability: The vulnerability is being exploited in the wild

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.

ATP series
USG series
VPN series
USG FLEX series
ZyWALL
USG20W-VPN
USG FLEX 50W

Install updates from vendor's website.

ATP series - update to 5.36 Patch 2
USG series - update to 4.73 Patch 2
ZyWALL - update to 4.73 Patch 2
VPN series - update to 5.36 Patch 2
USG20W-VPN - update to 5.36 Patch 2
USG FLEX 50W - update to 5.36 Patch 2
USG FLEX series - update to 5.36 Patch 2

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

• Multiple vulnerabilities in Zyxel firewalls