CVE-2004-0257: Netbsd

Medium severity, CVSS 5.0. EPSS: 2.5% chance of exploitation in the next 30 days.

OpenBSD 3.4 and NetBSD 1.6 and 1.6.1 allow remote attackers to cause a denial of service (crash) by sending an IPv6 packet with a small MTU to a listening port and then issuing a TCP connect to that port.

Affected products

• Netbsd Netbsd: version 1.6 only; version 1.6.1 only
• OpenBSD OpenBSD: version 3.0 only; version 3.1 only; version 3.2 only; version 3.3 only; version 3.4 only

Published 2004-11-23. Last modified 2026-06-16.