The remote Debian host is missing a security-related update.
Several vulnerabilities were discovered in BIND, a DNS server implementation. The Common Vulnerabilities and Exposures project identifies the following problems : - CVE-2017-3136 Oleg Gorokhov of Yandex discovered that BIND does not properly handle certain queries when using DNS64 with the 'break-dnssec yes;' option, allowing a remote attacker to cause a denial-of-service. - CVE-2017-3137 It was discovered that BIND makes incorrect assumptions about the ordering of records in the answer section of a response containing CNAME or DNAME resource records, leading to situations where BIND exits with an assertion failure. An attacker can take advantage of this condition to cause a denial-of-service. - CVE-2017-3138 Mike Lalumiere of Dyn, Inc. discovered that BIND can exit with a REQUIRE assertion failure if it receives a null command string on its control channel. Note that the fix applied in Debian is only applied as a hardening measure. Details about the issue can be found at https://kb.isc.org/article/AA-01471 .
Upgrade the bind9 packages. For the stable distribution (jessie), these problems have been fixed in version 1:9.9.5.dfsg-9+deb8u11.