The issue allows remote attackers to bypass CSRF protection by manipulating the HTTP Referer header. This is due to the reliance on a substring check for CSRF protection, which can be exploited by placing the required admin/developer/ URI within a query string in the Referer header. The vulnerability was found in the core/admin/modules/developer/ header.php file and was patched in the core/inc/bigtree/admin.php file.