diff --git a/core/modules/file/file.install b/core/modules/file/file.install
index 3ca855e..4a384c1 100644
--- a/core/modules/file/file.install
+++ b/core/modules/file/file.install
@@ -197,8 +197,9 @@ function file_requirements($phase) {
   // Check the server's ability to indicate upload progress.
   if ($phase == 'runtime') {
     $implementation = file_progress_implementation();
-    $apache = strpos($_SERVER['SERVER_SOFTWARE'], 'Apache') !== FALSE;
-    $fastcgi = strpos($_SERVER['SERVER_SOFTWARE'], 'mod_fastcgi') !== FALSE || strpos($_SERVER["SERVER_SOFTWARE"], 'mod_fcgi') !== FALSE;
+    $software = Drupal::request()->server->get('SERVER_SOFTWARE')
+    $apache = strpos($software, 'Apache') !== FALSE;
+    $fastcgi = strpos($software, 'mod_fastcgi') !== FALSE || strpos($software, 'mod_fcgi') !== FALSE;
     $description = NULL;
     if (!$apache) {
       $value = t('Not enabled');
diff --git a/core/modules/file/file.module b/core/modules/file/file.module
index 18dae26..e0286ca 100644
--- a/core/modules/file/file.module
+++ b/core/modules/file/file.module
@@ -738,8 +738,8 @@ function file_cron() {
 function file_ajax_upload() {
   $form_parents = func_get_args();
   $form_build_id = (string) array_pop($form_parents);
-
-  if (empty($_POST['form_build_id']) || $form_build_id != $_POST['form_build_id']) {
+  $request = Drupal::request()->request->get('form_build_id');
+  if (empty($request) || $form_build_id != $request) {
     // Invalid request.
     drupal_set_message(t('An unrecoverable error occurred. The uploaded file likely exceeded the maximum file size (@size) that this server supports.', array('@size' => format_size(file_upload_max_size()))), 'error');
     $response = new AjaxResponse();
@@ -1178,7 +1178,8 @@ function file_managed_file_submit($form, &$form_state) {
  */
 function file_managed_file_save_upload($element) {
   $upload_name = implode('_', $element['#parents']);
-  if (empty($_FILES['files']['name'][$upload_name])) {
+  $files = Drupal::request()->files->all();
+  if (empty($files['files']['name'][$upload_name])) {
     return FALSE;
   }
 
@@ -1190,8 +1191,8 @@ function file_managed_file_save_upload($element) {
   }
 
   // Save attached files to the database.
-  $files_uploaded = $element['#multiple'] && count(array_filter($_FILES['files']['name'][$upload_name])) > 0;
-  $files_uploaded |= !$element['#multiple'] && !empty($_FILES['files']['name'][$upload_name]);
+  $files_uploaded = $element['#multiple'] && count(array_filter($files['files']['name'][$upload_name])) > 0;
+  $files_uploaded |= !$element['#multiple'] && !empty($files['files']['name'][$upload_name]);
   if ($files_uploaded) {
     if (!$files = file_save_upload($upload_name, $element['#upload_validators'], $destination)) {
       watchdog('file', 'The file upload failed. %upload', array('%upload' => $upload_name));