CVE-2023-4398
Zyxel · published 2023-11-28
Source record Collected from the National Vulnerability Database (NVD)
Description
Description by Zyxel Corporation via the CVE Program.
An integer overflow vulnerability in the source code of the QuickSec IPSec toolkit used in the VPN feature of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, and VPN series firmware versions 4.30 through 5.37, could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions on an affected device by sending a crafted IKE packet.
Status at the source
- NVD status: Modified
Affected products, as the source lists them
| Vendor | Product | Versions |
|---|---|---|
| Zyxel | ATP series firmware | versions 4.32 through 5.37: affected |
| Zyxel | USG FLEX series firmware | versions 4.50 through 5.37: affected |
| Zyxel | USG FLEX 50(W) series firmware | versions 4.16 through 5.37: affected |
| Zyxel | USG20(W)-VPN series firmware | versions 4.16 through 5.37: affected |
| Zyxel | VPN series firmware | versions 4.30 through 5.37: affected |
Added by CISA-ADP (Authorized Data Publisher)
| Vendor | Product | Versions |
|---|---|---|
| zyxel | atp_firmware | 4.32 – 5.37 and earlier: affected |
| zyxel | usg_flex_firmware | 4.50 – 5.37 and earlier: affected |
| zyxel | usg_flex_50w_firmware | 4.16 – 5.37 and earlier: affected |
| zyxel | usg20w-vpn_firmware | 4.16 – 5.37 and earlier: affected |
| zyxel | vpn_firmware | 5.30 – 5.37 and earlier: affected |
Products named in NVD's CPE match criteria (1)
cpe:2.3:o:zyxel:zld:*:*:*:*:*:*:*:*
DeSpy has not checked any unit, hardware revision or firmware. A product missing here is not a statement that it is unaffected.
Scores, as their sources published them
- CVSS 3.1: 7.5 HIGH — as published by Zyxel Corporation (Secondary)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1: 7.5 HIGH — as published by NIST (Primary)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - SSVC — CISA's assessment (SSVC 2.0.3, CISA Coordinator): Exploitation: none · Automatable: yes · Technical impact: partial
DeSpy does not score records. These are the sources' own values.
Weaknesses
Sources
References the source lists
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps
Source dates: published 2023-11-28, last changed 2026-06-17. DeSpy's copy of this version is dated 2026-09-28.
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