The remote Debian host is missing a security-related update.
Several denial-of-service vulnerabilities (assertion failures) were discovered in BIND, a DNS server implementation. - CVE-2016-9131 A crafted upstream response to an ANY query could cause an assertion failure. - CVE-2016-9147 A crafted upstream response with self-contradicting DNSSEC data could cause an assertion failure. - CVE-2016-9444 Specially crafted upstream responses with a DS record could cause an assertion failure. These vulnerabilities predominantly affect DNS servers providing recursive service. Client queries to authoritative-only servers cannot trigger these assertion failures. These vulnerabilities are present whether or not DNSSEC validation is enabled in the server configuration.
Upgrade the bind9 packages. For the stable distribution (jessie), these problems have been fixed in version 1:9.9.5.dfsg-9+deb8u9.