CVE-2015-2937

MediaWiki anterior a 1.19.24, 1.2x anterior a 1.23.9 y 1.24.x anterior a 1.24.2, cuando se utiliza HHVM o Zend PHP, permite a atacantes remotos causar una denegación de servicio ('quadratic blowup' y consumo de memoria) a través de un fichero XML que contiene una declaración de entidad con un reemplazamiento de cadena de texto larga y muchas referencias a esta entidad, una vulnerabilidad diferente a CVE-2015-2942.

In MediaWiki before 1.23.9, one could circumvent the SVG MIME blacklist for embedded resources. This allowed an attacker to embed JavaScript in the SVG. In MediaWiki before 1.23.9, the SVG filter to prevent injecting JavaScript using animate elements was incorrect. In MediaWiki before 1.23.9, a stored XSS vulnerability exists due to the way attributes were expanded in MediaWiki's Html class, in combination with LanguageConverter substitutions. In MediaWiki before 1.23.9, MediaWiki's SVG filtering could be bypassed with entity encoding under the Zend interpreter. This could be used to inject JavaScript. In MediaWiki before 1.23.9, one could bypass the style filtering for SVG files to load external resources. This could violate the anonymity of users viewing the SVG. In MediaWiki before 1.23.9, MediaWiki versions using PBKDF2 for password hashing are vulnerable to DoS attacks using extremely long passwords. In MediaWiki before 1.23.9, MediaWiki is vulnerable to Quadratic Blowup DoS attacks, under both HHVM and Zend PHP. In MediaWiki before 1.23.9, the MediaWiki feature allowing a user to preview another user's custom JavaScript could be abused for privilege escalation. In MediaWiki before 1.23.9, function names were not sanitized in Lua error backtraces, which could lead to XSS. In MediaWiki before 1.23.9, the CheckUser extension did not prevent CSRF attacks on the form allowing checkusers to look up sensitive information about other users. Since the use of CheckUser is logged, the CSRF could be abused to defame a trusted user or flood the logs with noise. The mediawiki package has been updated to version 1.23.9, fixing these issues and other bugs.