The CentralAuth extension for MediaWiki 1.19.x before 1.19.8, 1.20.x before 1.20.7, and 1.21.x before 1.21.2 caches a valid CentralAuthUser object in the centralauth_User cookie even when a user has not successfully logged in, which allows remote attackers to bypass authentication without a password.
Incomplete blacklist vulnerability in Sanitizer::checkCss in MediaWiki before 1.19.9, 1.20.x before 1.20.8, and 1.21.x before 1.21.3 allows remote attackers to conduct cross-site scripting (XSS) attacks via a \b (backspace) character in CSS.
Incomplete blacklist vulnerability in Sanitizer::checkCss in MediaWiki before 1.19.9, 1.20.x before 1.20.8, and 1.21.x before 1.21.3 allows remote attackers to conduct cross-site scripting (XSS) attacks via certain non-ASCII characters in CSS, as demonstrated using variations of "expression" containing (1) full width characters or (2) IPA extensions, which are converted and rendered by Internet Explorer.
The CleanChanges extension for MediaWiki before 1.19.9, 1.20.x before 1.20.8, and 1.21.x before 1.21.3, when "Group changes by page in recent changes and watchlist" is enabled, allows remote attackers to obtain sensitive information (revision-deleted IPs) via the Recent Changes page.
Cross-site request forgery (CSRF) vulnerability in the CentralAuth extension for MediaWiki before 1.19.9, 1.20.x before 1.20.8, and 1.21.x before 1.21.3 allows remote attackers to hijack the authentication of users for requests that login via vectors involving image loading.
Cross-site scripting (XSS) vulnerability in the ZeroRatedMobileAccess extension for MediaWiki 1.19.x before 1.19.9, 1.20.x before 1.20.8, and 1.21.x before 1.21.3 allows remote attackers to inject arbitrary web script or HTML via the "to" parameter to index.php.
includes/resourceloader/ResourceLoaderContext.php in MediaWiki 1.19.x before 1.19.8, 1.20.x before 1.20.7, and 1.21.x before 1.21.2 allows remote attackers to obtain sensitive information via a "<" (open angle bracket) character in the lang parameter to w/load.php, which reveals the installation path in an error message.
(1) ApiBlock.php, (2) ApiCreateAccount.php, (3) ApiLogin.php, (4) ApiMain.php, (5) ApiQueryDeletedrevs.php, (6) ApiTokens.php, and (7) ApiUnblock.php in includes/api/ in MediaWiki 1.19.x before 1.19.8, 1.20.x before 1.20.7, and 1.21.x before 1.21.2 allow remote attackers to obtain CSRF tokens and bypass the cross-site request forgery (CSRF) protection mechanism via a JSONP request to wiki/api.php.
Cross-site scripting (XSS) vulnerability in contrib/example.php in the SyntaxHighlight GeSHi extension for MediaWiki, possibly as downloaded before September 2013, allows remote attackers to inject arbitrary web script or HTML via the PATH_INFO.
Cross-site request forgery (CSRF) vulnerability in api/ApiQueryCheckUser.php in the CheckUser extension for MediaWiki, possibly Checkuser before 2.3, allows remote attackers to hijack the authentication of arbitrary users for requests that "perform sensitive write actions" via unspecified vectors.