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.

Multiple cross-site scripting (XSS) vulnerabilities in repo/includes/EntityView.php in the Wikibase 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 allow (1) remote attackers to inject arbitrary web script or HTML via a label in the "In other languages" section or (2) remote administrators to inject arbitrary web script or HTML via a description.

Cross-site scripting (XSS) vulnerability in pages/TalkpageHistoryView.php in the LiquidThreads (LQT) extension 2.x and possibly 3.x for 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 inject arbitrary web script or HTML via a thread subject.

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.

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 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 1.22.x before 1.22.2, 1.21.x before 1.21.5, and 1.19.x before 1.19.11, when DjVu or PDF file upload support is enabled, allows remote attackers to execute arbitrary commands via shell metacharacters in (1) the page parameter to includes/media/DjVu.php; (2) the w parameter (aka width field) to thumb.php, which is not properly handled by includes/media/PdfHandler_body.php; and possibly unspecified vectors in (3) includes/media/Bitmap.php and (4) includes/media/ImageHandler.php.

mediawiki: sqlite information leak

An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. When installing with a pre-existing data directory that has weak permissions, the SQLite files are created with file mode 0644, i.e., world readable to local users. These files include credentials data.

mediawiki: GrowthExperiments growthmanagementorlist API allows blocked users to enroll as mentors

In the GrowthExperiments extension for MediaWiki through 1.39, the growthmanagementorlist API allows blocked users (blocked in ApiManageMentorList) to enroll as mentors or edit any of their mentorship-related properties.

MediaWiki: XSS in widget placement

An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. E-Widgets does widget replacement in HTML attributes, which can lead to XSS, because widget authors often do not expect that their widget is executed in an HTML attribute context.

MediaWiki: Remote DoS

An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. SpecialMobileHistory allows remote attackers to cause a denial of service because database queries are slow.

An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. CheckUser TokenManager insecurely uses AES-CTR encryption with a repeated (aka re-used) nonce, allowing an adversary to decrypt.

An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. There is XSS in Wikibase date formatting via wikibase-time-precision-* fields. This allows JavaScript execution by staff/admin users who do not intentionally have the editsitejs capability.

mediawiki: Edits with the performer suppressed still show the performer in results from the CheckUser extension

An issue was discovered in the CheckUser extension for MediaWiki through 1.39.x. Various components of this extension can expose information on the performer of edits and logged actions. This information should not allow public viewing: it is supposed to be viewable only by users with suppression rights.

An issue was discovered in the CheckUser extension for MediaWiki through 1.42.1. The API can expose suppressed information for log events. (The log_deleted attribute is not applied to entries.)

An issue was discovered in the GuMaxDD skin for MediaWiki through 1.42.1. There is stored XSS via MediaWiki:Sidebar top-level menu entries.

An issue was discovered in the Nimbus skin for MediaWiki through 1.42.1. There is Stored XSS via MediaWiki:Nimbus-sidebar menu and submenu entries.

An issue was discovered in the CheckUser extension for MediaWiki through 1.42.1. The Special:Investigate feature can expose suppressed information for log events. (TimelineService does not support properly suppressing.)

An issue was discovered in the ArticleRatings extension for MediaWiki through 1.42.1. Special:ChangeRating allows CSRF to alter data via a GET request.

An issue was discovered in the Tempo skin for MediaWiki through 1.42.1. There is stored XSS via MediaWiki:Sidebar top-level menu entries.