MediaWiki before 1.19.18, 1.20.x through 1.22.x before 1.22.9, and 1.23.x before 1.23.2 does not enforce an IFRAME protection mechanism for transcluded pages, which makes it easier for remote attackers to conduct clickjacking attacks via a crafted web site.
https://lists.wikimedia.org/pipermail/mediawiki-announce/2014-July/000157.html
http://www.mandriva.com/security/advisories?name=MDVSA-2014:153
http://www.debian.org/security/2014/dsa-3011
http://secunia.com/advisories/59738