• Vulnerability: XSS
  • Affected Software: YOP Poll (20,000+ active installations)
  • Affected Version: 6.0.2
  • Patched Version: 6.0.3
  • Risk: Medium
  • Vendor Contacted: 10/25/2018
  • Vendor Fix: 11/26/2018
  • Public Disclosure: 02/05/2019
CVSS

6.1 Medium CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Details

The YOP poll WordPress plugin is vulnerable to reflected XSS as it echoes the poll_id parameter without proper encoding.

Successful exploitation allows an attacker to execute JavaScript in the context of the application in the name of an attacked user. This in turn enables an attacker to bypass CSRF protection and thus perform any actions the legitimate user can perform, as well as read data which the user can access.

Proof of Concept
http://192.168.0.103/wordpress/wp-admin/admin.php?page=yop-polls&action=view-votes&poll_id=1'"><img+src%3Dx+onerror%3Dalert(1)>
Code
yop-poll/admin/views/viewpollvotes.php:                
<input type="hidden" name="poll_id" value="<?php echo $_REQUEST['poll_id']; ?>">
Timeline
  • 10/25/2018 Requested email address via contact form
  • 10/25/2018 Vendor responds, advisory sent
  • 11/26/2018 Vendor releases fix
  • 02/05/2019 Confirmed fix & Disclosure