The dns_db_findrdataset function in db.c in named in ISC BIND 9.4 before 9.4.3-P3, 9.5 before 9.5.1-P3, and 9.6 before 9.6.1-P1, when configured as a master server, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via an ANY record in the prerequisite section of a crafted dynamic update message, as exploited in the wild in July 2009.