MediaWiki before 1.19.6 and 1.20.x before 1.20.5 does not allow extensions to prevent password changes without using both Special:PasswordReset and Special:ChangePassword, which allows remote attackers to bypass the intended restrictions of an extension that only implements one of these blocks.
https://bugzilla.wikimedia.org/show_bug.cgi?id=46590
http://security.gentoo.org/glsa/glsa-201310-21.xml
http://secunia.com/advisories/55433
http://lists.wikimedia.org/pipermail/mediawiki-announce/2013-April/000129.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/106293.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/105825.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/105784.html