The remote Debian host is missing a security-related update.
Multiple vulnerabilities have been discovered in pdns, an authoritative DNS server. The Common Vulnerabilities and Exposures project identifies the following problems : - CVE-2016-5426 / CVE-2016-5427 Florian Heinz and Martin Kluge reported that the PowerDNS Authoritative Server accepts queries with a qname's length larger than 255 bytes and does not properly handle dot inside labels. A remote, unauthenticated attacker can take advantage of these flaws to cause abnormal load on the PowerDNS backend by sending specially crafted DNS queries, potentially leading to a denial of service. - CVE-2016-6172 It was reported that a malicious primary DNS server can crash a secondary PowerDNS server due to improper restriction of zone size limits. This update adds a feature to limit AXFR sizes in response to this flaw.
Upgrade the pdns packages. For the stable distribution (jessie), these problems have been fixed in version 3.4.1-4+deb8u6.