CVE-2023-27991: OS Command Injection

Q: What is CVE-2023-27991?

CVE-2023-27991 is a post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35.

Q: What is the severity of CVE-2023-27991?

CVE-2023-27991 has a severity value of 8.8 (high).

Q: How can I fix CVE-2023-27991?

To fix CVE-2023-27991, you should update the affected firmware versions to 5.36 for ATP series and USG FLEX series, and to 4.30 for USG20(W)-VPN and VPN series.

Q: Where can I find more information about CVE-2023-27991?

You can find more information about CVE-2023-27991 at the following link: [Zyxel Security Advisory](https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-xss-vulnerability-and-post-authentication-command-injection-vulnerability-in-firewalls)

Published Apr 24, 2023

Updated

The post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow an authenticated attacker to execute some OS commands remotely.

Affected Software

38 affected components

Zyxel Atp200 Firmware>=4.32<5.36

Zyxel ATP200

Zyxel Atp100 Firmware>=4.32<5.36

Zyxel Atp100

Zyxel Atp700 Firmware>=4.32<5.36

Zyxel Atp700

Zyxel Atp500 Firmware>=4.32<5.36

Zyxel ATP500

Zyxel Atp100w Firmware>=4.32<5.36

Zyxel Atp100w

Zyxel Atp800 Firmware>=4.32<5.36

Zyxel ATP800

Zyxel Usg Flex 100 Firmware>=4.50<5.36

Zyxel Usg Flex 100

Zyxel Usg Flex 50 Firmware>=4.50<5.36

Zyxel USG FLEX 50

Zyxel USG FLEX 200 firmware>=4.50<5.36

Zyxel USG FLEX 200

Zyxel USG FLEX 500 firmware>=4.50<5.36

Zyxel USG FLEX 500

Zyxel USG FLEX 700 firmware>=4.50<5.36

Zyxel USG FLEX 700

Zyxel Usg Flex 100w Firmware>=4.50<5.36

Zyxel Usg Flex 100w

Zyxel Usg 20w-vpn Firmware>=4.16<5.36

Zyxel Usg 20w-vpn

Zyxel Usg Flex 50w Firmware>=4.16<5.36

Zyxel Usg Flex 50w

Zyxel Usg20-vpn Firmware>=4.30<5.36

Zyxel USG20-VPN

Zyxel Vpn100 Firmware>=4.30<5.36

Zyxel Vpn100

Zyxel Vpn1000 Firmware>=4.30<5.36

Zyxel Vpn1000

Zyxel Vpn300 Firmware>=4.30<5.36

Zyxel Vpn300

Zyxel Vpn50 Firmware>=4.30<5.36

Zyxel Vpn50

Event History

Apr 24, 2023

CVE Published

via MITRE·12:00 AM

Data Sourced

via MITRE·12:00 AM

DescriptionSeverityWeakness

Frequently Asked Questions

What is CVE-2023-27991?

CVE-2023-27991 is a post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35.

Which Zyxel products are affected by CVE-2023-27991?

Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series.

What is the severity of CVE-2023-27991?

CVE-2023-27991 has a severity value of 8.8 (high).

How can I fix CVE-2023-27991?

To fix CVE-2023-27991, you should update the affected firmware versions to 5.36 for ATP series and USG FLEX series, and to 4.30 for USG20(W)-VPN and VPN series.

Where can I find more information about CVE-2023-27991?