The Post Grid Master – Custom Post Types, Taxonomies & Ajax Filter Everything with Infinite Scroll, Load More, Pagination & Shortcode Builder plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 3.4.12 via the 'locate_template' function. This makes it possible for unauthenticated attackers to include and execute arbitrary files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where images and other “safe” file types can be uploaded and included. The file included must have a .php extension.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.