Integer underflow in the isakmp_id_print for TCPDUMP 3.8.1 and earlier allows remote attackers to cause a denial of service (crash) via an ISAKMP packet with an Identification payload with a length that becomes less than 8 during byte order conversion, which causes an out-of-bounds read, as demonstrated by the Striker ISAKMP Protocol Test Suite.
http://www.tcpdump.org/tcpdump-changes.txt