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…

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.