CVE-2023-33009 - CVE House
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Status published Critical CVE-2023-33009

A buffer overflow vulnerability in the notification function in Zyxel...

Vulnerability Description

A buffer overflow vulnerability in the notification function in Zyxel ATP series firmware versions 4.60 through 5.36 Patch 1, USG FLEX series firmware versions 4.60 through 5.36 Patch 1, USG FLEX 50(W) firmware versions 4.60 through 5.36 Patch 1, USG20(W)-VPN firmware versions 4.60 through 5.36 Patch 1, VPN series firmware versions 4.60 through 5.36 Patch 1, ZyWALL/USG series firmware versions 4.60 through 4.73 Patch 1, could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and even a remote code execution on an affected device.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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Affected Vendor

Affected Software

ATP series firmware, USG FLEX series firmware, USG FLEX 50(W) firmware, USG20(W)-VPN firmware, VPN series firmware, ZyWALL/USG series firmware
Vulnerable Versions:
4.60 through 5.36 Patch 1, 4.60 through 4.73 Patch 1

Timeline

Official Publish: May 24th, 2023
Last Modified: October 21st, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses (CWE)

CWE-120

MITRE ATT&CK TTPs

T1203 Exploitation for Client Execution
Execution
T1068 Exploitation for Privilege Escalation
Privilege Escalation
T1055 Process Injection
Defense Evasion
T1105 Ingress Tool Transfer
Command and Control