The IMGspider plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the 'upload_img_file' function in all versions up to, and including, 2.3.10. This makes it possible for authenticated attackers, with contributor-level and above permissions, to upload arbitrary files on the affected site's server which may make remote code execution possible.
https://plugins.trac.wordpress.org/changeset/3107741/imgspider
https://plugins.trac.wordpress.org/browser/imgspider/tags/2.3.10/classes/post.class.php#L122