The verify_host_key function in sshconnect.c in the client in OpenSSH 6.6 and earlier allows remote servers to trigger the skipping of SSHFP DNS RR checking by presenting an unacceptable HostCertificate.
http://www.ubuntu.com/usn/USN-2164-1
http://www.securityfocus.com/bid/66459
http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html
http://www.mandriva.com/security/advisories?name=MDVSA-2015:095
http://www.mandriva.com/security/advisories?name=MDVSA-2014:068
http://www.debian.org/security/2014/dsa-2894
http://secunia.com/advisories/59855
http://rhn.redhat.com/errata/RHSA-2015-0425.html
http://rhn.redhat.com/errata/RHSA-2014-1552.html
http://openwall.com/lists/oss-security/2014/03/26/7
http://marc.info/?l=bugtraq&m=141576985122836&w=2
http://lists.fedoraproject.org/pipermail/package-announce/2014-May/133537.html
http://lists.fedoraproject.org/pipermail/package-announce/2014-June/134026.html
http://aix.software.ibm.com/aix/efixes/security/openssh_advisory4.asc