Multiple cross-site request forgery (CSRF) vulnerabilities in MediaWiki 1.17.x before 1.17.3 and 1.18.x before 1.18.2 allow remote attackers to hijack the authentication of users with the block permission for requests that (1) block a user via a request to the Block module or (2) unblock a user via a request to the Unblock module.
https://exchange.xforce.ibmcloud.com/vulnerabilities/78911
https://bugzilla.wikimedia.org/show_bug.cgi?id=34212
http://www.securityfocus.com/bid/52689
http://www.openwall.com/lists/oss-security/2012/03/24/1
http://www.openwall.com/lists/oss-security/2012/03/22/9
http://secunia.com/advisories/48504
http://lists.wikimedia.org/pipermail/mediawiki-announce/2012-March/000110.html
http://lists.wikimedia.org/pipermail/mediawiki-announce/2012-March/000109.html