Click to Chat < 3.18.1 - 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.

Exploit shortcode:

[ht-ctc-chat pre_filled='" onmouseover="alert(1)']