The (1) session_save_path (2) ini_set and (3) error_log functions in PHP 4.4.7 and earlier and PHP 5 5.2.3 and earlier when invoked from a .htaccess file allow remote attackers to bypass safe_mode and open_basedir restrictions and possibly execute arbitrary commands as demonstrated using (a) php_value (b) php_flag and (c) directives in .htaccess.