The remote Debian host is missing a security-related update.
It was discovered that a maliciously crafted query can cause ISC's BIND DNS server (named) to crash if both Response Policy Zones (RPZ) and DNS64 (a bridge between IPv4 and IPv6 networks) are enabled. It is uncommon for both of these options to be used in combination, so very few systems will be affected by this problem in practice. This update also corrects an additional regression caused by the fix for CVE-2016-8864, which was applied in a previous security update.
Upgrade the bind9 packages. For the stable distribution (jessie), this problem has been fixed in version 1:9.9.5.dfsg-9+deb8u10.