OpenStack keystonemiddleware (formerly python-keystoneclient) 0.x before 0.11.0 and 1.x before 1.2.0 disables certification verification when the "insecure" option is set in a paste configuration (paste.ini) file regardless of the value, which allows remote attackers to conduct man-in-the-middle attacks via a crafted certificate.
https://bugs.launchpad.net/python-keystoneclient/+bug/1353315
http://www.ubuntu.com/usn/USN-2705-1
http://www.securityfocus.com/bid/69864
http://www.openwall.com/lists/oss-security/2014/09/25/51
http://secunia.com/advisories/62709
http://rhn.redhat.com/errata/RHSA-2015-0020.html