The remote Debian host is missing a security-related update.
Jayachandran Palanisamy of Cygate AB reported that BIND, a DNS server implementation, was improperly sequencing cleanup operations, leading in some cases to a use-after-free error, triggering an assertion failure and crash in named.
Upgrade the bind9 packages. For the oldstable distribution (jessie), this problem has been fixed in version 1:9.9.5.dfsg-9+deb8u15. For the stable distribution (stretch), this problem has been fixed in version 1:9.10.3.dfsg.P4-12.3+deb9u4.