Carousel, Slider, Gallery by WP Carousel < 2.5.3 - Contributor+ Stored XSS

The plugin does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.

PoC

Exploit shortcode: [wcfgallery ids=‘1’ speed=“1}’ onmouseover=‘alert(1)’ data-swiper-more='{test:1”] Note: the ids are the attachment ids.