CVE-2003-1491: Kerio Personal Firewall

High severity, CVSS 7.5. EPSS: 2.4% chance of exploitation in the next 30 days.

Kerio Personal Firewall (KPF) 2.1.4 has a default rule to accept incoming packets from DNS (UDP port 53), which allows remote attackers to bypass the firewall filters via packets with a source port of 53.

Affected products

• Kerio Personal Firewall: version 2.1.4 only

Published 2003-12-31. Last modified 2026-06-16.