The following extensions had cross-site scripting (XSS) vulnerabilities: * geo * MetavidWiki * wikihiero
These vulnerabilities are exploitable even if the extensions are disabled. If you have any of these extensions installed, please update them immediately.
Many shared hosting services have the php.ini setting "register_globals" enabled, despite the fact that it is known to be detrimental to security.
A new automated vulnerability scanner has found a large number of security vulnerabilities in MediaWiki extensions, when register_globals is enabled. Unless you are sure you have register_globals disabled, the following extensions should be immediately updated:
Cross-site scripting vulnerabilities: * Call * ChangeAuthor * EditOwn * SignDocument * TemplateLink * WatchSubpages * WhoIsWatching * php/ext/MediaWiki
Arbitrary script inclusion vulnerabilities: * CategoryIntersection * Makebot * PasswordReset * regexBlock * SemanticCalendar * SemanticForms * SemanticMediaWiki * SocialProfile * SpamRegex * StalePages * TodoTasks * WhiteList * Wikidata
All these extensions are vulnerable regardless of whether they are enabled in LocalSettings.php. They only need to be installed, with their installation directory accessible from the public internet.
Downloads in .tar.gz form for all these MediaWiki extensions are available from: http://www.mediawiki.org/wiki/Special:ExtensionDistributor
Or using a subversion client from: http://svn.wikimedia.org/svnroot/mediawiki/trunk/extensions
-- Tim Starling