The checkCss function in includes/Sanitizer.php in the wikitext parser in MediaWiki before 1.16.3 does not properly validate Cascading Style Sheets (CSS) token sequences, which allows remote attackers to conduct cross-site scripting (XSS) attacks or obtain sensitive information by using the \2f\2a and \2a\2f hex strings to surround CSS comments.
https://exchange.xforce.ibmcloud.com/vulnerabilities/66738
https://bugzilla.wikimedia.org/show_bug.cgi?id=28450
https://bugzilla.redhat.com/show_bug.cgi?id=696360
https://bugzilla.redhat.com/show_bug.cgi?id=695577
http://www.vupen.com/english/advisories/2011/1151
http://www.vupen.com/english/advisories/2011/1100
http://www.vupen.com/english/advisories/2011/0978
http://www.securityfocus.com/bid/47354
http://www.debian.org/security/2011/dsa-2366
http://secunia.com/advisories/44142
http://openwall.com/lists/oss-security/2011/04/13/15
http://lists.wikimedia.org/pipermail/mediawiki-announce/2011-April/000096.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-April/059235.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-April/059232.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-April/058910.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-April/058588.html