The RSS Aggregator – RSS Import, News Feeds, Feed to Post, and Autoblogging plugin for WordPress is vulnerable to unauthorized use of functionality due to a missing capability check on the wprss_ajax_send_premium_support function in all versions up to, and including, 4.23.12. This makes it possible for authenticated attackers, with Subscriber-level access and above, to send premium support requests with an attacker-controlled subject line and email address to support allowing them to impersonate the site owner. License information may also be leaked.
https://plugins.trac.wordpress.org/changeset/3168468/wp-rss-aggregator/trunk/includes/admin-help.php
https://plugins.trac.wordpress.org/browser/wp-rss-aggregator/trunk/includes/admin-help.php#L274