The WP Datepicker plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'wpdp_get_selected_datepicker' parameter in all versions up to, and including, 2.1.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L553
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L552
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L423
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L416
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L415
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L409
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L408
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L402
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L401
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L377
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L361
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L359
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L271
https://plugins.trac.wordpress.org/browser/wp-datepicker/tags/2.1.3/inc/wpdp_settings.php#L267