6.5
MEDIUM
CVE-2023-6399
Zyxel ATP/USG FLEX/USG20/USG FLEX H Format String Denial of Service Vulnerability
Description

A format string vulnerability in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1, and USG FLEX H series firmware versions from 1.10 through 1.10 Patch 1 could allow an authenticated IPSec VPN user to cause DoS conditions against the “deviceid” daemon by sending a crafted hostname to an affected device if it has the “Device Insight” feature enabled.

INFO

Published Date :

Feb. 20, 2024, 2:15 a.m.

Last Modified :

Jan. 21, 2025, 6:36 p.m.

Remotely Exploitable :

Yes !

Impact Score :

3.6

Exploitability Score :

2.8
Affected Products

The following products are affected by CVE-2023-6399 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Zyxel usg20-vpn_firmware
2 Zyxel usg20w-vpn_firmware
3 Zyxel usg_20w-vpn_firmware
4 Zyxel usg_flex_100_firmware
5 Zyxel usg_flex_100w_firmware
6 Zyxel usg_flex_200_firmware
7 Zyxel usg_flex_50_firmware
8 Zyxel usg_flex_500_firmware
9 Zyxel usg_flex_50w_firmware
10 Zyxel usg_flex_700_firmware
11 Zyxel atp100_firmware
12 Zyxel atp100w_firmware
13 Zyxel atp200_firmware
14 Zyxel atp500_firmware
15 Zyxel atp700_firmware
16 Zyxel atp800_firmware
17 Zyxel atp100
18 Zyxel atp200
19 Zyxel atp500
20 Zyxel atp100w
21 Zyxel atp700
22 Zyxel atp800
23 Zyxel usg_flex_100
24 Zyxel usg_flex_50
25 Zyxel usg_flex_200
26 Zyxel usg_flex_500
27 Zyxel usg_flex_700
28 Zyxel usg_flex_100w
29 Zyxel usg_flex_50w
30 Zyxel usg20-vpn
31 Zyxel usg20w-vpn
32 Zyxel usg_flex_100ax
33 Zyxel uos
34 Zyxel usg_flex_100h
35 Zyxel usg_flex_200h
36 Zyxel usg_flex_200hp
37 Zyxel usg_flex_500h
38 Zyxel usg_flex_700h
39 Zyxel usg_flex_100ax_firmware
40 Zyxel usg_flex_100h_firmware
41 Zyxel usg_flex_200h_firmware
42 Zyxel usg_flex_200hp_firmware
43 Zyxel usg_flex_500h_firmware
44 Zyxel usg_flex_700h_firmware
45 Zyxel usg_flex_100hp
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2023-6399.

URL Resource
https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024 Vendor Advisory
https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024 Vendor Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2023-6399 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2023-6399 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jan. 21, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE NIST NVD-CWE-noinfo
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:atp100_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:atp100_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:atp100_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:atp100:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:atp100w_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:atp100w_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:atp100w_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:atp100w:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:atp200_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:atp200_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:atp200_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:atp200:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:atp500_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:atp500_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:atp500_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:atp500:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:atp700_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:atp700_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:atp700_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:atp700:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:atp800_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:atp800_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:atp800_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:atp800:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:uos:1.10:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:uos:1.10:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_100h:-:*:*:*:*:*:*:* cpe:2.3:h:zyxel:usg_flex_100hp:-:*:*:*:*:*:*:* cpe:2.3:h:zyxel:usg_flex_200h:-:*:*:*:*:*:*:* cpe:2.3:h:zyxel:usg_flex_200hp:-:*:*:*:*:*:*:* cpe:2.3:h:zyxel:usg_flex_500h:-:*:*:*:*:*:*:* cpe:2.3:h:zyxel:usg_flex_700h:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg20-vpn_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg20-vpn_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg20-vpn_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg20-vpn:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg20w-vpn_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg20w-vpn_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg20w-vpn_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg20w-vpn:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_100_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_100_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_100_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_100:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_100ax_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_100ax_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_100ax_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_100ax:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_100h_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_100h_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_100h_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_100h:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_100w_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_100w_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_100w_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_100w:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_200_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_200_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_200_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_200:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_200h_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_200h_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_200h_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_200h:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_200hp_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_200hp_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_200hp_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_200hp:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_500_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_500_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_500_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_500:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_500h_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_500h_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_500h_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_500h:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_50_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_50_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_50_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_50:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_50w_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_50w_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_50w_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_50w:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_700_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_700_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_700_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_700:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:usg_flex_700h_firmware:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.37 *cpe:2.3:o:zyxel:usg_flex_700h_firmware:5.37:-:*:*:*:*:*:* *cpe:2.3:o:zyxel:usg_flex_700h_firmware:5.37:patch1:*:*:*:*:*:* OR cpe:2.3:h:zyxel:usg_flex_700h:-:*:*:*:*:*:*:*
    Changed Reference Type https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024 No Types Assigned https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024 Vendor Advisory
    Changed Reference Type https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024 No Types Assigned https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024 Vendor Advisory
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Feb. 21, 2024

    Action Type Old Value New Value
    Changed Description A format string vulnerability in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, and USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1 could allow an authenticated IPSec VPN user to cause DoS conditions against the “deviceid” daemon by sending a crafted hostname to an affected device if it has the “Device Insight” feature enabled. A format string vulnerability in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1, and USG FLEX H series firmware versions from 1.10 through 1.10 Patch 1 could allow an authenticated IPSec VPN user to cause DoS conditions against the “deviceid” daemon by sending a crafted hostname to an affected device if it has the “Device Insight” feature enabled.
  • CVE Received by [email protected]

    Feb. 20, 2024

    Action Type Old Value New Value
    Added Description A format string vulnerability in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, and USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1 could allow an authenticated IPSec VPN user to cause DoS conditions against the “deviceid” daemon by sending a crafted hostname to an affected device if it has the “Device Insight” feature enabled.
    Added Reference Zyxel Corporation https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024 [No types assigned]
    Added CWE Zyxel Corporation CWE-134
    Added CVSS V3.1 Zyxel Corporation AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2023-6399 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2023-6399 weaknesses.

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability