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.