FreeBSD 5.1 and earlier, and Mac OS X before 10.3.4, allows remote attackers to cause a denial of service (resource exhaustion of memory buffers and system crash) via a large number of out-of-sequence TCP packets, which prevents the operating system from creating new connections.
ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-04:04.tcp.asc
lists.seifried.org/pipermail/security/2004-May/003743.html
www.idefense.com/application/poi/display?id=78&type=vulnerabilities
www.kb.cert.org/vuls/id/395670
www.osvdb.org/4124
www.securityfocus.com/bid/9792
exchange.xforce.ibmcloud.com/vulnerabilities/15369