The map_meta_cap function in wp-includes/capabilities.php in WordPress 3.4.x before 3.4.2, when the multisite feature is enabled, does not properly assign the unfiltered_html capability, which allows remote authenticated users to bypass intended access restrictions and conduct cross-site scripting (XSS) attacks by leveraging the Administrator or Editor role and composing crafted text.
codex.wordpress.org/Version_3.4.1
codex.wordpress.org/Version_3.4.2
core.trac.wordpress.org/changeset?old_path=%2Ftags%2F3.4.1&old=21780&new_path=%2Ftags%2F3.4.2&new=21780#file23
core.trac.wordpress.org/changeset?reponame=&new=21153%40branches%2F3.4&old=21076%40trunk#file16
openwall.com/lists/oss-security/2012/09/12/17
www.openwall.com/lists/oss-security/2012/07/02/1
www.openwall.com/lists/oss-security/2012/07/08/1