CVE-2023-34140: Buffer Overflow

Published Jul 17, 2023
·
Updated

A buffer overflow vulnerability in the Zyxel ATP series firmware versions 4.32 through 5.36 Patch 2, USG FLEX series firmware versions 4.50 through 5.36 Patch 2, USG FLEX 50(W) series firmware versions 4.16 through 5.36 Patch 2, USG20(W)-VPN series firmware versions 4.16 through 5.36 Patch 2, VPN series firmware versions 4.30 through 5.36 Patch 2, NXC2500 firmware versions 6.10(AAIG.0) through 6.10(AAIG.3), and NXC5500 firmware versions 6.10(AAOS.0) through 6.10(AAOS.4), could allow an unauthenticated, LAN-based attacker to cause denial of service (DoS) conditions by sending a crafted request to the CAPWAP daemon.

Affected Software

96 affected components
Zyxel Usg 20w-vpn Firmware>=4.16<5.37
Zyxel Usg 20w-vpn
Zyxel Usg 2200-vpn Firmware>=4.30<5.37
Zyxel Usg 2200-vpn
Zyxel Usg Flex 100 Firmware>=4.50<5.37
Zyxel Usg Flex 100
Zyxel Usg Flex 100w Firmware>=4.50<5.37
Zyxel Usg Flex 100w
Zyxel USG FLEX 200 firmware>=4.50<5.37
Zyxel USG FLEX 200
Zyxel Usg Flex 50 Firmware>=4.50<5.37
Zyxel USG FLEX 50
Zyxel USG FLEX 500 firmware>=4.50<5.37
Zyxel USG FLEX 500
Zyxel Usg Flex 50w Firmware>=4.50<5.37
Zyxel Usg Flex 50w
Zyxel USG FLEX 700 firmware>=4.50<5.37
Zyxel USG FLEX 700
Zyxel Zywall Atp100 Firmware>=4.32<5.37
Zyxel Zywall Atp100
Zyxel Zywall Atp100w Firmware>=4.32<5.37
Zyxel Zywall Atp100w
Zyxel Zywall Atp200 Firmware>=4.32<5.37
Zyxel Zywall Atp200
Zyxel Zywall Atp500 Firmware>=4.32<5.37
Zyxel Zywall Atp500
Zyxel Zywall Atp700 Firmware>=4.32<5.37
Zyxel Zywall Atp700
Zyxel Zywall Atp800 Firmware>=4.32<5.37
Zyxel Zywall Atp800
Zyxel Zywall Vpn100 Firmware>=4.30<5.37
Zyxel Zywall Vpn100
Zyxel Zywall Vpn2s Firmware>=4.30<5.37
Zyxel Zywall Vpn2s
Zyxel Zywall Vpn300 Firmware>=4.30<5.37
Zyxel Zywall Vpn300
Zyxel Zywall Vpn50 Firmware>=4.30<5.37
Zyxel Zywall Vpn50
Zyxel Zywall Vpn 100 Firmware>=4.30<5.37
Zyxel Zywall Vpn 100
Zyxel Zywall Vpn 300 Firmware>=4.30<5.37
Zyxel Zywall Vpn 300
Zyxel Zywall Vpn 50 Firmware>=4.30<5.37
Zyxel Zywall Vpn 50
Zyxel NXC2500 firmware>=6.10\(aaig.0\)<=6.10\(aaig.3\)
Zyxel NXC2500
Zyxel NXC5500 firmware>=6.10\(aaos.0\)<=6.10\(aaos.4\)
Zyxel NXC5500
All of the following
Zyxel Usg 20w-vpn Firmware>=4.16<5.37
Zyxel Usg 20w-vpn
All of the following
Zyxel Usg 2200-vpn Firmware>=4.30<5.37
Zyxel Usg 2200-vpn
All of the following
Zyxel Usg Flex 100 Firmware>=4.50<5.37
Zyxel Usg Flex 100
All of the following
Zyxel Usg Flex 100w Firmware>=4.50<5.37
Zyxel Usg Flex 100w
All of the following
Zyxel USG FLEX 200 firmware>=4.50<5.37
Zyxel USG FLEX 200
All of the following
Zyxel Usg Flex 50 Firmware>=4.50<5.37
Zyxel USG FLEX 50
All of the following
Zyxel USG FLEX 500 firmware>=4.50<5.37
Zyxel USG FLEX 500
All of the following
Zyxel Usg Flex 50w Firmware>=4.50<5.37
Zyxel Usg Flex 50w
All of the following
Zyxel USG FLEX 700 firmware>=4.50<5.37
Zyxel USG FLEX 700
All of the following
Zyxel Zywall Atp100 Firmware>=4.32<5.37
Zyxel Zywall Atp100
All of the following
Zyxel Zywall Atp100w Firmware>=4.32<5.37
Zyxel Zywall Atp100w
All of the following
Zyxel Zywall Atp200 Firmware>=4.32<5.37
Zyxel Zywall Atp200
All of the following
Zyxel Zywall Atp500 Firmware>=4.32<5.37
Zyxel Zywall Atp500
All of the following
Zyxel Zywall Atp700 Firmware>=4.32<5.37
Zyxel Zywall Atp700
All of the following
Zyxel Zywall Atp800 Firmware>=4.32<5.37
Zyxel Zywall Atp800
All of the following
Zyxel Zywall Vpn100 Firmware>=4.30<5.37
Zyxel Zywall Vpn100
All of the following
Zyxel Zywall Vpn2s Firmware>=4.30<5.37
Zyxel Zywall Vpn2s
All of the following
Zyxel Zywall Vpn300 Firmware>=4.30<5.37
Zyxel Zywall Vpn300
All of the following
Zyxel Zywall Vpn50 Firmware>=4.30<5.37
Zyxel Zywall Vpn50
All of the following
Zyxel Zywall Vpn 100 Firmware>=4.30<5.37
Zyxel Zywall Vpn 100
All of the following
Zyxel Zywall Vpn 300 Firmware>=4.30<5.37
Zyxel Zywall Vpn 300
All of the following
Zyxel Zywall Vpn 50 Firmware>=4.30<5.37
Zyxel Zywall Vpn 50
All of the following
Zyxel NXC2500 firmware>=6.10\(aaig.0\)<=6.10\(aaig.3\)
Zyxel NXC2500
All of the following
Zyxel NXC5500 firmware>=6.10\(aaos.0\)<=6.10\(aaos.4\)
Zyxel NXC5500

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Zyxel ATP series firmware to a version that resolves this vulnerability.

    Fixed in 5.36 Patch 2
  2. Upgrade

    Upgrade USG FLEX series firmware to a version that resolves this vulnerability.

    Fixed in 5.36 Patch 2
  3. Upgrade

    Upgrade USG FLEX 50(W) series firmware to a version that resolves this vulnerability.

    Fixed in 5.36 Patch 2
  4. Upgrade

    Upgrade USG20(W)-VPN series firmware to a version that resolves this vulnerability.

    Fixed in 5.36 Patch 2
  5. Upgrade

    Upgrade VPN series firmware to a version that resolves this vulnerability.

    Fixed in 5.36 Patch 2
  6. Upgrade

    Upgrade NXC2500 firmware to a version that resolves this vulnerability.

    Fixed in 6.10(AAIG.3)
  7. Upgrade

    Upgrade NXC5500 firmware to a version that resolves this vulnerability.

    Fixed in 6.10(AAOS.4)

Event History

Jul 17, 2023
CVE Published
via MITRE·05:49 PM
Data Sourced
via MITRE·05:49 PM
DescriptionSeverityWeakness
Data Sourced
06:15 PM
DescriptionSeverity
Data Sourced
via NVD·06:15 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2023-34140?

The severity of CVE-2023-34140 is medium with a score of 6.5.

2

Which Zyxel products are affected by CVE-2023-34140?

Zyxel ATP series firmware versions 4.32 through 5.36 Patch 2, USG FLEX series firmware versions 4.50 through 5.36 Patch 2, USG FLEX 50(W) series firmware versions 4.16 through 5.36 Patch 2, and USG20(W)-VPN series firmware versions 4.16 through 5.36 Patch 2 are affected by CVE-2023-34140.

3

How can I fix CVE-2023-34140?

To fix CVE-2023-34140, update your Zyxel firmware to versions 5.37 for affected models.

4

What is the Common Vulnerabilities and Exposures (CVE) ID of this vulnerability?

The Common Vulnerabilities and Exposures (CVE) ID of this vulnerability is CVE-2023-34140.

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