The TCP reassembly function in the inet module in FreeBSD 8.3 before p16, 8.4 before p9, 9.1 before p12, 9.2 before p5, and 10.0 before p2 allows remote attackers to cause a denial of service (undefined memory access and system crash) or possibly read system memory via multiple crafted packets, related to moving a reassemble queue entry to the segment list when the queue is full.
http://www.securitytracker.com/id/1030172
http://www.securityfocus.com/bid/67153
http://www.freebsd.org/security/advisories/FreeBSD-SA-14:08.tcp.asc
http://www.debian.org/security/2014/dsa-2952