The mirroring support (-M, --use-mirrors) in Python Pip before 1.5 uses insecure DNS querying and authenticity checks which allows attackers to perform man-in-the-middle attacks.
lists.fedoraproject.org/pipermail/package-announce/2015-April/155248.html
lists.fedoraproject.org/pipermail/package-announce/2015-April/155291.html
www.openwall.com/lists/oss-security/2013/08/21/17
www.openwall.com/lists/oss-security/2013/08/21/18
www.securityfocus.com/bid/77520
bugzilla.redhat.com/show_bug.cgi?id=CVE-2013-5123
bugzilla.suse.com/show_bug.cgi?id=CVE-2013-5123
security-tracker.debian.org/tracker/CVE-2013-5123