The inet module in FreeBSD 10.2x before 10.2-PRERELEASE, 10.2-BETA2-p2, 10.2-RC1-p1, 10.1x before 10.1-RELEASE-p16, 9.x before 9.3-STABLE, 9.3-RELEASE-p21, and 8.x before 8.4-STABLE, 8.4-RELEASE-p35 on systems with VNET enabled and at least 16 VNET instances allows remote attackers to cause a denial of service (mbuf consumption) via multiple concurrent TCP connections.