includes/upload/UploadBase.php in MediaWiki before 1.19.12, 1.20.x and 1.21.x before 1.21.6, and 1.22.x before 1.22.3 does not prevent use of invalid namespaces in SVG files, which allows remote attackers to conduct cross-site scripting (XSS) attacks via an SVG upload, as demonstrated by use of a W3C XHTML namespace in conjunction with an IFRAME element.
includes/User.php in MediaWiki before 1.19.12, 1.20.x and 1.21.x before 1.21.6, and 1.22.x before 1.22.3 terminates validation of a user token upon encountering the first incorrect character, which makes it easier for remote attackers to obtain access via a brute-force attack that relies on timing differences in responses to incorrect token guesses.
Cross-site scripting (XSS) vulnerability in the formatHTML function in includes/api/ApiFormatBase.php in MediaWiki before 1.19.12, 1.20.x and 1.21.x before 1.21.6, and 1.22.x before 1.22.3 allows remote attackers to inject arbitrary web script or HTML via a crafted string located after http:// in the text parameter to api.php.
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.
MediaWiki before 1.19.6 and 1.20.x before 1.20.5 allows remote attackers to conduct cross-site scripting (XSS) attacks, as demonstrated by a CDATA section containing valid UTF-7 encoded sequences in a SVG file, which is then incorrectly interpreted as UTF-8 by Chrome and Firefox.