Directory traversal vulnerability in index.php in Simple Machines Forum (SMF) 1.0 before 1.0.15 and 1.1 before 1.1.7 allows remote authenticated users to configure arbitrary local files for execution via directory traversal sequences in the value of the theme_dir field during a jsoption action, related to Sources/QueryString.php and Sources/Themes.php, as demonstrated by a local .gif file in attachments/ with PHP code that was uploaded through a profile2 action to index.php.