Actively exploited in the wild
Zyxel Multiple Firewalls OS Command Injection Vulnerability
Zyxel - Multiple Firewalls · Listed in the CISA KEV since 2023-05-31. This indicates confirmed attacks in production environments.
Required action: Apply updates per vendor instructions.
CVE-2023-28771
CriticalCVSS 9.8KEVSummary
Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series 4.60 through 5.35, USG FLEX series 4.60 through 5.35, and ATP series 4.60 through 5.35. An unauthenticated attacker could execute OS commands remotely by sending crafted packets to an affected device.
Risk Assessment
An unauthenticated attacker could take control of the edge device, potentially compromising network security.
Recommendation
Update Zyxel device firmware to the latest version. Restrict management interface access from untrusted networks.
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Original NVD description (English source)
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.