CVE-2001-0402: Darren Reed Ipfilter

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

IPFilter 3.4.16 and earlier does not include sufficient session information in its cache, which allows remote attackers to bypass access restrictions by sending fragmented packets to a restricted port after sending unfragmented packets to an unrestricted port.

Affected products

• Darren Reed Ipfilter: up to and including 3.4.16
• Freebsd Freebsd: up to and including 4.1
• OpenBSD OpenBSD: version 2.8 only

Published 2001-06-18. Last modified 2026-06-16.