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01 Record

CVE-2023-4398

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

HighPUBLISHEDCNA: Zyxel
CNA base score7.5 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

02 Description

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

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.88% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 58.7% of scored records. A rank, not a probability.
NVD base score
7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2023-11-28 01:48Z2 YR AGO
Last updated
2024-10-17 17:38Z2 YR AGO
Reserved
2023-08-17
Assigning CNA
Zyxel
Record state
PUBLISHED
Severity
High (CVSS 7.5)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
  • CWE-190Integer Overflow or WraparoundBase
Data version
5.1
Document digest
e22f85b0a72ab6a191afeee9bfdf38405a3d6cca2aa1a826996a2aec88daea28

05 Affected products

VendorProductVersionsPlatforms
ZyxelATP series firmwareversions 4.32 through 5.37—
ZyxelUSG FLEX series firmwareversions 4.50 through 5.37—
ZyxelUSG FLEX 50(W) series firmwareversions 4.16 through 5.37—
ZyxelUSG20(W)-VPN series firmwareversions 4.16 through 5.37—
ZyxelVPN series firmwareversions 4.30 through 5.37—
zyxelatp_firmware4.32 to 5.37—
zyxelusg_flex_firmware4.50 to 5.37—
zyxelusg_flex_50w_firmware4.16 to 5.37—
zyxelusg20w-vpn_firmware4.16 to 5.37—
zyxelvpn_firmware5.30 to 5.37—

06 References