CRITICAL CISA KEV

CVE-2023-28771

CVSS v3

9.8

CRITICAL

EPSS Score

94.3%

exploit probability

CISA KEV

Yes

known exploited

Exploitation

SSVC status

Description

Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series firmware versions 4.60 through 5.35, USG FLEX series firmware versions 4.60 through 5.35, and ATP series firmware versions 4.60 through 5.35, which could allow an unauthenticated attacker to execute some OS commands remotely by sending crafted packets to an affected device.

CISA Known Exploited Vulnerability

Date Added
5/31/2023
Patch Due Date
6/21/2023
Ransomware Use
Unknown

Technical details

Published
4/25/2023

Frequently asked questions

What is CVE-2023-28771?

Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series firmware versions 4.60 through 5.35, USG FLEX series firmware versions 4.60 through 5.35, and ATP series firmware versions 4.60 through 5.35, which could allow an unauthenticated attacker to execute some OS commands remotely by sending crafted packets to an affected device.

Is CVE-2023-28771 actively exploited?

Yes. CVE-2023-28771 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 6/21/2023.

What is the CVSS score for CVE-2023-28771?

CVE-2023-28771 has a CVSS v3 base score of 9.8 (CRITICAL severity).

Is CVE-2023-28771 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.