CVE-2016-7072

An issue has been found in PowerDNS Authoritative Server before 3.4.11 and
4.0.2 allowing a remote, unauthenticated attacker to cause a denial of
service by opening a large number of TCP connections to the web server. If
the web server runs out of file descriptors, it triggers an exception and
terminates the whole PowerDNS process. While it’s more complicated for an
unauthorized attacker to make the web server run out of file descriptors
since its connection will be closed just after being accepted, it might
still be possible.