CVE-2023-33011

Name: CVE-2023-33011
Creator: NVD / NIST
Published: 2023-07-17T18:15:09.397+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 0.30%

Last modified Jun 17, 2026

CVE-2023-33011 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. A format string vulnerability in the Zyxel ATP series firmware versions 5.10 through 5.36 Patch 2, USG FLEX series firmware versions 5.00 through 5.36 Patch 2, USG FLEX 50(W) series firmware versions 5.10 through 5.36 Patch 2, USG20(W)-VPN series firmware versions 5.10 through 5.36 Patch 2, and VPN series firmware versions 5.00 through 5.36 Patch 2, could allow an unauthenticated, LAN-based attacker to execute some OS commands by using a crafted PPPoE configuration on an affected device when the cloud management mode is enabled.. EPSS estimates a 0.30% chance of exploitation in the next 30 days.

Description

A format string vulnerability in the Zyxel ATP series firmware versions 5.10 through 5.36 Patch 2, USG FLEX series firmware versions 5.00 through 5.36 Patch 2, USG FLEX 50(W) series firmware versions 5.10 through 5.36 Patch 2, USG20(W)-VPN series firmware versions 5.10 through 5.36 Patch 2, and VPN series firmware versions 5.00 through 5.36 Patch 2, could allow an unauthenticated, LAN-based attacker to execute some OS commands by using a crafted PPPoE configuration on an affected device when the cloud management mode is enabled.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

0.30%

21.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Zyxel	Usg 2200-Vpn Firmware	>= 5.00, < 5.37
Zyxel	Usg Flex 100 Firmware	>= 5.00, < 5.37
Zyxel	Usg Flex 100w Firmware	>= 5.00, < 5.37
Zyxel	Usg Flex 200 Firmware	>= 5.00, < 5.37
Zyxel	Usg Flex 50 Firmware	>= 5.00, < 5.37
Zyxel	Usg Flex 500 Firmware	>= 5.00, < 5.37
Zyxel	Usg Flex 50w Firmware	>= 5.00, < 5.37
Zyxel	Usg Flex 700 Firmware	>= 5.00, < 5.37
Zyxel	Zywall Vpn100 Firmware	>= 5.00, < 5.37
Zyxel	Zywall Vpn2s Firmware	>= 5.00, < 5.37
Zyxel	Zywall Vpn300 Firmware	>= 5.00, < 5.37
Zyxel	Zywall Vpn50 Firmware	>= 5.00, < 5.37
Zyxel	Zywall Vpn 100 Firmware	>= 5.00, < 5.37
Zyxel	Zywall Vpn 300 Firmware	>= 5.00, < 5.37
Zyxel	Zywall Vpn 50 Firmware	>= 5.00, < 5.37
Zyxel	Usg 20w-Vpn Firmware	>= 5.10, < 5.37
Zyxel	Zywall Atp100 Firmware	>= 5.10, < 5.37
Zyxel	Zywall Atp100w Firmware	>= 5.10, < 5.37
Zyxel	Zywall Atp200 Firmware	>= 5.10, < 5.37
Zyxel	Zywall Atp500 Firmware	>= 5.10, < 5.37
Zyxel	Zywall Atp700 Firmware	>= 5.10, < 5.37
Zyxel	Zywall Atp800 Firmware	>= 5.10, < 5.37

References

Timeline

Published: Jul 17, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-33011?

How severe is CVE-2023-33011?

CVE-2023-33011 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.

How do I fix CVE-2023-33011?

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-2023-33011?

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

Scan your code now

Source: NVD / NIST