api.php in MediaWiki before 1.15.5 does not prevent use of public caching headers for private data, which allows remote attackers to bypass intended access restrictions and obtain sensitive information by retrieving documents from an HTTP proxy cache that has been used by a victim.
https://bugzilla.wikimedia.org/show_bug.cgi?id=24565
https://bugzilla.redhat.com/show_bug.cgi?id=620226
https://bugzilla.redhat.com/show_bug.cgi?id=620224
http://www.securityfocus.com/bid/42019
http://svn.wikimedia.org/viewvc/mediawiki?view=revision&revision=69776
http://openwall.com/lists/oss-security/2010/07/29/4
http://lists.wikimedia.org/pipermail/mediawiki-announce/2010-July/000092.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-April/059235.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-April/059232.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-April/058910.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-April/058588.html