osCommerce 2.3.4.1 has XSS vulnerability via the authenticated user entering the XSS payload into the title section of newsletters.
https://github.com/gburton/CE-Phoenix/commits/master
https://github.com/aslanemre/cve-2020-29070/blob/main/CVE-2020-29070
https://forums.oscommerce.com/forum/17-news-and-announcements/