ISC BIND 9.8.x through 9.8.4-P1 and 9.9.x through 9.9.2-P1, in certain configurations involving DNS64 with a Response Policy Zone that lacks an AAAA rewrite rule, allows remote attackers to cause a denial of service (assertion failure and named daemon exit) via a query for an AAAA record.
https://kb.isc.org/article/AA-00855/
http://www.ubuntu.com/usn/USN-2693-1