serf is vulnerable to man-in-the-middle (MitM) attacks. The vulnerability existed because of an improper handling of a NUL byte in a domain name in the subject’s Common Name (CN), which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority.
lists.opensuse.org/opensuse-updates/2014-08/msg00038.html
secunia.com/advisories/59584
secunia.com/advisories/60721
ubuntu.com/usn/usn-2315-1
www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html
www.securityfocus.com/bid/69238
groups.google.com/forum/#!topic/serf-dev/NvgPoK6sFsc
security-tracker.debian.org/tracker/CVE-2014-3504
security.gentoo.org/glsa/201610-05
subversion.apache.org/security/CVE-2014-3522-advisory.txt