Zyxel USG / ATP / VPN < 5.37 Multiple Vulnerabilities

medium Nessus Plugin ID 186480


The remote security gateway is affected by multiple vulnerabilities.


Firmware version of the Zyxel USG, ATP, or VPN is less than 5.37. This means the Zyxel device is vulnerable to the following:

- An integer overflow vulnerability in the source code of the QuickSec IPSec toolkit could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions on an affected device by sending a crafted IKE packet. (CVE-2023-4398)

- An improper input validation vulnerability in the “Quagga” package could allow an authenticated local attacker to access configuration files on an affected device. (CVE-2023-35136)

- An improper privilege management vulnerability in the debug CLI command could allow an authenticated local attacker to access system files on an affected device. (CVE-2023-37925)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


Upgrade to Zyxel USG / ATP / VPN to 5.37 or later.

See Also


Plugin Details

Severity: Medium

ID: 186480

File Name: zyxel_usg_multiple_vulnerabilities.nasl

Version: 1.3

Type: combined

Family: Firewalls

Published: 11/30/2023

Updated: 12/5/2023

Supported Sensors: Nessus

Risk Information


Risk Factor: Low

Score: 3.6


Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:N/A:N

CVSS Score Source: CVE-2023-5797


Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/h:zyxel:usg_flex

Required KB Items: installed_sw/Zyxel Unified Security Gateway (USG)

Exploit Ease: No known exploits are available

Patch Publication Date: 11/28/2023

Vulnerability Publication Date: 11/28/2023

Reference Information

CVE: CVE-2023-35136, CVE-2023-37925, CVE-2023-37926, CVE-2023-4398, CVE-2023-5650, CVE-2023-5797

IAVA: 2023-A-0655