Closes #773.

Unspecified vulnerability in ISC BIND 9.4 before 9.4.3-P4, 9.5 before
9.5.2-P1, 9.6 before 9.6.1-P2, 9.7 beta before 9.7.0b3, and 9.0.x through
9.3.x with DNSSEC validation enabled and checking disabled (CD), allows
remote attackers to conduct DNS cache poisoning attacks via additional
sections in a response sent for resolution of a recursive client query,
which is not properly handled when the response is processed "at the same
time as requesting DNSSEC records (DO)."

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>