Absolute path traversal vulnerability in Cross-RSS (wp-cross-rss) plugin 1.7 for WordPress allows remote attackers to read arbitrary files via a full pathname in the rss parameter to proxy.php.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2014-4858
http://codevigilant.com/disclosure/wp-plugin-cross-rss-local-file-inclusion/