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CVE-2023-33009

CRITICALCVSS 9.8/10Actively ExploitedEPSS 28.14%

Last modified

CVE-2023-33009 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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.. CISA has confirmed active exploitation in the wild. EPSS estimates a 28.14% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
9.8/10

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

EPSS Probability
28.14%

97.9th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by .

Weakness Enumeration

Affected Software

VendorProductVersions
ZyxelAtp100 Firmware>= 4.60, < 5.36
ZyxelAtp100 Firmware5.36
ZyxelAtp200 Firmware>= 4.60, < 5.36
ZyxelAtp200 Firmware5.36
ZyxelAtp500 Firmware>= 4.60, < 5.36
ZyxelAtp500 Firmware5.36
ZyxelAtp100w Firmware>= 4.60, < 5.36
ZyxelAtp100w Firmware5.36
ZyxelAtp700 Firmware>= 4.60, < 5.36
ZyxelAtp700 Firmware5.36
ZyxelAtp800 Firmware>= 4.60, < 5.36
ZyxelAtp800 Firmware5.36
ZyxelUsg Flex 100 Firmware>= 4.60, < 5.36
ZyxelUsg Flex 100 Firmware5.36
ZyxelUsg Flex 50 Firmware>= 4.60, < 5.36
ZyxelUsg Flex 50 Firmware5.36
ZyxelUsg Flex 200 Firmware>= 4.60, < 5.36
ZyxelUsg Flex 200 Firmware5.36
ZyxelUsg Flex 500 Firmware>= 4.60, < 5.36
ZyxelUsg Flex 500 Firmware5.36
ZyxelUsg Flex 700 Firmware>= 4.60, < 5.36
ZyxelUsg Flex 700 Firmware5.36
ZyxelUsg Flex 100w Firmware>= 4.60, < 5.36
ZyxelUsg Flex 100w Firmware5.36
ZyxelUsg Flex 50w Firmware>= 4.60, < 5.36
ZyxelUsg Flex 50w Firmware5.36
ZyxelUsg 20w-Vpn Firmware>= 4.60, < 5.36
ZyxelUsg 20w-Vpn Firmware5.36
ZyxelVpn100 Firmware>= 4.60, < 5.36
ZyxelVpn100 Firmware5.36
ZyxelVpn50 Firmware>= 4.60, < 5.36
ZyxelVpn50 Firmware5.36
ZyxelVpn300 Firmware>= 4.60, < 5.36
ZyxelVpn300 Firmware5.36
ZyxelVpn1000 Firmware>= 4.60, < 5.36
ZyxelVpn1000 Firmware5.36
ZyxelUsg20-Vpn Firmware>= 4.60, < 5.36
ZyxelUsg20-Vpn Firmware5.36
ZyxelUsg 40 Firmware>= 4.60, < 4.73
ZyxelUsg 40 Firmware4.73
ZyxelUsg 40w Firmware>= 4.60, < 4.73
ZyxelUsg 40w Firmware4.73
ZyxelUsg 60w Firmware>= 4.60, < 4.73
ZyxelUsg 60w Firmware4.73
ZyxelUsg 60 Firmware>= 4.60, < 4.73
ZyxelUsg 60 Firmware4.73

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2023-33009?
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.
How severe is CVE-2023-33009?
CVE-2023-33009 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 28.14% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.
How do I fix CVE-2023-33009?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-33009?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST