Description
Cross-site scripting (XSS) vulnerability in flash/FlashMediaElement.as in MediaElement.js before 2.21.0, as used in WordPress before 4.5.2, allows remote attackers to inject arbitrary web script or HTML via an obfuscated form of the jsinitfunction parameter, as demonstrated by "jsinitfunctio%gn."
Remediation
References
https://wordpress.org/news/2016/05/wordpress-4-5-2/
http://www.openwall.com/lists/oss-security/2016/05/07/2
https://codex.wordpress.org/Version_4.5.2
https://core.trac.wordpress.org/changeset/37371
https://github.com/johndyer/mediaelement/commit/34834eef8ac830b9145df169ec22016a4350f06e
https://github.com/johndyer/mediaelement/blob/master/changelog.md
https://wpvulndb.com/vulnerabilities/8488
https://gist.github.com/cure53/df34ea68c26441f3ae98f821ba1feb9c
http://www.securitytracker.com/id/1035818