Is CVE-2023-28771 actively exploited?

Yes. CVE-2023-28771 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2023-28771 be exploited remotely?

The attack vector of CVE-2023-28771 has not been classified yet.

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

CVE-2023-28771 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2023-28771

HIGHCISA KEVIN THE WILD

CVE-2023-28771

Published: May 31, 2023

EPSS:94.35%probability of exploitation in 30 daysPercentile:100.0th

Official Description

Zyxel ATP, USG FLEX, VPN, and ZyWALL/USG firewalls allow for improper error message handling which could allow an unauthenticated attacker to execute OS commands remotely by sending crafted packets to an affected device.

NVD Source

CISA KEV Advisory

Zyxel Multiple Firewalls OS Command Injection Vulnerability

Added to KEV: 2023-05-31Federal patch deadline: 2023-06-21

Required Action (CISA)

Apply updates per vendor instructions.

Risk Analysis

Zyxel ATP, USG FLEX, VPN, and ZyWALL/USG firewalls contain an improper error message handling vulnerability. This allows an unauthenticated attacker to execute OS commands remotely by sending crafted packets. The high EPSS score of 0.94346 indicates a very high likelihood of exploitation.

This vulnerability is actively exploited in the wild and is included in CISA's KEV catalog. Its remote exploitability by unauthenticated attackers makes it a critical threat.

Recommended Action

Update Zyxel ATP, USG FLEX, VPN, and ZyWALL/USG firewalls to the latest firmware versions to address this improper error message handling vulnerability.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2023-28771 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2023-28771 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.