------------------------------------------------------------------------ Cross-Site Scripting vulnerability in Booking Calendar WordPress Plugin ------------------------------------------------------------------------ Edwin Molenaar, July 2016 ------------------------------------------------------------------------ Abstract ------------------------------------------------------------------------ A Cross-Site Scripting vulnerability was found in the Booking Calendar WordPress Plugin. This issue allows an attacker to perform a wide variety of actions, such as stealing users' session tokens, or performing arbitrary actions on their behalf. In order to exploit this issue, the attacker has to lure/force a victim into opening a malicious website/link. ------------------------------------------------------------------------ OVE ID ------------------------------------------------------------------------ OVE-20160714-0003 ------------------------------------------------------------------------ Tested versions ------------------------------------------------------------------------ These issues were successfully tested on Booking Calendar WordPress Plugin version 6.2. ------------------------------------------------------------------------ Fix ------------------------------------------------------------------------ This issue is resolved in Booking Calendar version 6.2.1. ------------------------------------------------------------------------ Details ------------------------------------------------------------------------ https://sumofpwn.nl/advisory/2016/cross_site_scripting_vulnerability_in_booking_calendar_wordpress_plugin.html The vulnerability exists in the wpdev_bk_settings_form_labels() function from booking/lib/wpdev-settings-general.php (line 1492). All input field on the Booking > Settings > Fields page are vulnerable to Cross-Site Scripting, eg http:///wp-admin/admin.php?page=booking%2Fwpdev-booking.phpwpdev-booking-option&tab=form. Also all the form from the Booking > Settings > Import tab are vulnerable to Cross-Site Scripting, however a valid anti-CSRF token in this tab is required, eg http:///wp-admin/admin.php?page=booking%2Fwpdev-booking.phpwpdev-booking-option&tab=sync. Proof of concept ------------------------------------------------------------------------ Summer of Pwnage (https://sumofpwn.nl) is a Dutch community project. Its goal is to contribute to the security of popular, widely used OSS projects in a fun and educational way.