ajax.functions.php in the MailUp plugin before 1.3.3 for WordPress does not properly restrict access to unspecified Ajax functions, which allows remote attackers to modify plugin settings and conduct cross-site scripting (XSS) attacks by setting the wordpress_logged_in cookie. NOTE: this is due to an incomplete fix for a similar issue that was fixed in 1.3.2.

ajax.functions.php in the MailUp plugin before 1.3.2 for WordPress does not properly restrict access to unspecified Ajax functions, which allows remote attackers to modify plugin settings and conduct cross-site scripting (XSS) attacks via unspecified vectors related to "formData=save" requests, a different version than CVE-2013-0731.