Php - Access Control
PHP 5.2.5 does not enforce (a) open_basedir and (b) safe_mode_exec_dir restrictions for certain functions, which might allow local users to bypass intended access restrictions and call programs outside of the intended directory via the (1) exec, (2) system, (3) shell_exec, (4) passthru, or (5) popen functions, possibly involving pathnames such as "C:" drive notation.