medium
6.5
CWE
134
Advisory Published
Updated

CVE-2023-6399

First published: Tue Feb 20 2024(Updated: )

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.

Credit: security@zyxel.com.tw

Affected SoftwareAffected VersionHow to fix
Zyxel ATP series firmware>=4.32<=5.37 Patch 1
Zyxel USG FLEX series firmware>=4.50<=5.37 Patch 1
Zyxel USG FLEX 50(W) series firmware>=4.16<=5.37 Patch 1
Zyxel USG 20w-VPN Firmware>=4.16<=5.37 Patch 1
Zyxel USG FLEX h series firmware>=1.10<=1.10 Patch 1
All of
Any of
Zyxel ZyWall ATP100 Firmware>=5.10<5.37
Zyxel ZyWall ATP100 Firmware=5.37
Zyxel ZyWall ATP100 Firmware=5.37-patch1
Zyxel ATP100 Firmware
All of
Any of
Zyxel ATP100W Firmware>=5.10<5.37
Zyxel ATP100W Firmware=5.37
Zyxel ATP100W Firmware=5.37-patch1
Zyxel ATP100W Firmware
All of
Any of
Zyxel ATP200 firmware>=5.10<5.37
Zyxel ATP200 firmware=5.37
Zyxel ATP200 firmware=5.37-patch1
Zyxel Zywall ATP200
All of
Any of
Zyxel ATP500 Firmware>=5.10<5.37
Zyxel ATP500 Firmware=5.37
Zyxel ATP500 Firmware=5.37-patch1
Zyxel ATP500 Firmware
All of
Any of
Zyxel Zywall ATP700>=5.10<5.37
Zyxel Zywall ATP700=5.37
Zyxel Zywall ATP700=5.37-patch1
Zyxel ATP700 Firmware
All of
Any of
Zyxel Zywall ATP800 Firmware>=5.10<5.37
Zyxel Zywall ATP800 Firmware=5.37
Zyxel Zywall ATP800 Firmware=5.37-patch1
Zyxel Zywall ATP800 Firmware
All of
Any of
Zyxel USG Flex 100 firmware>=5.10<5.37
Zyxel USG Flex 100 firmware=5.37
Zyxel USG Flex 100 firmware=5.37-patch1
Zyxel USG Flex 100 firmware
All of
Any of
Zyxel USG FLEX 100ax firmware>=5.10<5.37
Zyxel USG FLEX 100ax firmware=5.37
Zyxel USG FLEX 100ax firmware=5.37-patch1
Zyxel USG FLEX 100ax firmware
All of
Any of
Zyxel USG FLEX 100ax firmware>=5.10<5.37
Zyxel USG FLEX 100ax firmware=5.37
Zyxel USG FLEX 100ax firmware=5.37-patch1
Zyxel USG Flex 100HP
All of
Any of
Zyxel USG FLEX 100w firmware>=5.10<5.37
Zyxel USG FLEX 100w firmware=5.37
Zyxel USG FLEX 100w firmware=5.37-patch1
Zyxel USG FLEX 100w firmware
All of
Any of
Zyxel USG FLEX firmware>=5.10<5.37
Zyxel USG FLEX firmware=5.37
Zyxel USG FLEX firmware=5.37-patch1
Zyxel USG FLEX 200 firmware
All of
Any of
Zyxel USG Flex 200HP Firmware>=5.10<5.37
Zyxel USG Flex 200HP Firmware=5.37
Zyxel USG Flex 200HP Firmware=5.37-patch1
Zyxel USG FLEX 200h firmware
All of
Any of
Zyxel USG Flex 200HP Firmware>=5.10<5.37
Zyxel USG Flex 200HP Firmware=5.37
Zyxel USG Flex 200HP Firmware=5.37-patch1
Zyxel USG Flex 200HP Firmware
All of
Any of
Zyxel USG FLEX firmware>=5.10<5.37
Zyxel USG FLEX firmware=5.37
Zyxel USG FLEX firmware=5.37-patch1
Zyxel USG FLEX 500 firmware
All of
Any of
Zyxel USG FLEX 500h>=5.10<5.37
Zyxel USG FLEX 500h=5.37
Zyxel USG FLEX 500h=5.37-patch1
Zyxel USG FLEX 500h firmware
All of
Any of
Zyxel USG FLEX firmware>=5.10<5.37
Zyxel USG FLEX firmware=5.37
Zyxel USG FLEX firmware=5.37-patch1
Zyxel USG FLEX 700 firmware
All of
Any of
Zyxel USG FLEX 700h firmware>=5.10<5.37
Zyxel USG FLEX 700h firmware=5.37
Zyxel USG FLEX 700h firmware=5.37-patch1
Zyxel USG FLEX 700h firmware
All of
Any of
Zyxel USG FLEX 50(W) series firmware>=5.10<5.37
Zyxel USG FLEX 50(W) series firmware=5.37
Zyxel USG FLEX 50(W) series firmware=5.37-patch1
Zyxel USG FLEX 50w
All of
Any of
Zyxel USG FLEX 50w>=5.10<5.37
Zyxel USG FLEX 50w=5.37
Zyxel USG FLEX 50w=5.37-patch1
Zyxel USG FLEX 50(W) series firmware
All of
Any of
Zyxel USG20W-VPN Firmware>=5.10<5.37
Zyxel USG20W-VPN Firmware=5.37
Zyxel USG20W-VPN Firmware=5.37-patch1
Zyxel USG20W-VPN Firmware
All of
Any of
Zyxel USG 20W-VPN Firmware>=5.10<5.37
Zyxel USG 20W-VPN Firmware=5.37
Zyxel USG 20W-VPN Firmware=5.37-patch1
Zyxel USG20W-VPN Firmware
All of
Any of
Zyxel UOS=1.10
Zyxel UOS=1.10-patch1
Any of
Zyxel USG Flex 100HP
Zyxel USG Flex 100HP
Zyxel USG FLEX 200h firmware
Zyxel USG Flex 200HP Firmware
Zyxel USG FLEX 500h firmware
Zyxel USG FLEX 700h firmware

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2023-6399?

    CVE-2023-6399 has a critical severity rating due to its potential impact when exploited.

  • How do I fix CVE-2023-6399?

    To fix CVE-2023-6399, update the affected Zyxel firmware versions to the patched releases.

  • Which products are affected by CVE-2023-6399?

    CVE-2023-6399 affects multiple Zyxel products including the ATP series, USG FLEX series, and USG20(VPN) series firmware versions.

  • What are the firmware versions impacted by CVE-2023-6399?

    The affected firmware versions range from 4.32 to 5.37 Patch 1 for the specified Zyxel devices.

  • Can CVE-2023-6399 lead to a remote code execution exploit?

    Yes, CVE-2023-6399 can be exploited through a format string vulnerability, potentially leading to remote code execution.

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