BIND 9 is an implementation of the Domain Name System (DNS) protocols. The named(8) daemon is an Internet Domain Name Server.
DNS Security Extensions (DNSSEC) provides data integrity, origin authentication and authenticated denial of existence to resolvers.
II. Problem Description
BIND 9 stores a cache of query names that are known to be failing due to misconfigured name servers or a broken chain of trust. Under high query loads, when DNSSEC validation is active, it is possible for a condition to arise in which data from this cache of failing queries could be used before it was fully initialized, triggering an assertion failure.
A remote attacker that is able to generate high volume of DNSSEC validation enabled queries can trigger the assertion failure that causes it to crash, resulting in a denial of service.
For a workaround and solution, check out the security advisory: FreeBSD-SA-12:05.bind.asc