SA-CORE-2018-004 for Drupal 7.34 or older

sa-core-2018-drupal-older-7.35.patch

diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 06acf93..d5963a0 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -2778,6 +2778,31 @@ function _drupal_bootstrap_variables() {
   // Load bootstrap modules.
   require_once DRUPAL_ROOT . '/includes/module.inc';
   module_load_all(TRUE);
+
+  // Sanitize the destination parameter (which is often used for redirects) to
+  // prevent open redirect attacks leading to other domains. Sanitize both
+  // $_GET['destination'] and $_REQUEST['destination'] to protect code that
+  // relies on either, but do not sanitize $_POST to avoid interfering with
+  // unrelated form submissions. The sanitization happens here because
+  // url_is_external() requires the variable system to be available.
+  if (isset($_GET['destination']) || isset($_REQUEST['destination'])) {
+    require_once DRUPAL_ROOT . '/includes/common.inc';
+    // If the destination is an external URL, remove it.
+    if (isset($_GET['destination']) && url_is_external($_GET['destination'])) {
+      unset($_GET['destination']);
+      unset($_REQUEST['destination']);
+    }
+    // Use the DrupalRequestSanitizer to ensure that the destination's query
+    // parameters are not dangerous.
+    if (isset($_GET['destination'])) {
+      DrupalRequestSanitizer::cleanDestination();
+    }
+    // If there's still something in $_REQUEST['destination'] that didn't come
+    // from $_GET, check it too.
+    if (isset($_REQUEST['destination']) && (!isset($_GET['destination']) || $_REQUEST['destination'] != $_GET['destination']) && url_is_external($_REQUEST['destination'])) {
+      unset($_REQUEST['destination']);
+    }
+  }
 }
 
 /**
diff --git a/includes/common.inc b/includes/common.inc
index d7dc47f..f61d1eb 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -611,8 +611,9 @@ function drupal_parse_url($url) {
   }
   // The 'q' parameter contains the path of the current page if clean URLs are
   // disabled. It overrides the 'path' of the URL when present, even if clean
-  // URLs are enabled, due to how Apache rewriting rules work.
-  if (isset($options['query']['q'])) {
+  // URLs are enabled, due to how Apache rewriting rules work. The path
+  // parameter must be a string.
+  if (isset($options['query']['q']) && is_string($options['query']['q'])) {
     $options['path'] = $options['query']['q'];
     unset($options['query']['q']);
   }
diff --git a/includes/request-sanitizer.inc b/includes/request-sanitizer.inc
index 1daa6b5..7214436 100644
--- a/includes/request-sanitizer.inc
+++ b/includes/request-sanitizer.inc
@@ -52,6 +52,38 @@ class DrupalRequestSanitizer {
   }
 
   /**
+   * Removes the destination if it is dangerous.
+   *
+   * Note this can only be called after common.inc has been included.
+   *
+   * @return bool
+   *   TRUE if the destination has been removed from $_GET, FALSE if not.
+   */
+  public static function cleanDestination() {
+    $dangerous_keys = array();
+    $log_sanitized_keys = variable_get('sanitize_input_logging', FALSE);
+
+    $parts = drupal_parse_url($_GET['destination']);
+    // If there is a query string, check its query parameters.
+    if (!empty($parts['query'])) {
+      $whitelist = variable_get('sanitize_input_whitelist', array());
+
+      self::stripDangerousValues($parts['query'], $whitelist, $dangerous_keys);
+      if (!empty($dangerous_keys)) {
+        // The destination is removed rather than sanitized to mirror the
+        // handling of external destinations.
+        unset($_GET['destination']);
+        unset($_REQUEST['destination']);
+        if ($log_sanitized_keys) {
+          trigger_error(format_string('Potentially unsafe destination removed from query string parameters (GET) because it contained the following keys: @keys', array('@keys' => implode(', ', $dangerous_keys))));
+        }
+        return TRUE;
+      }
+    }
+    return FALSE;
+  }
+
+  /**
    * Strips dangerous keys from the provided input.
    *
    * @param mixed $input
diff --git a/modules/file/file.module b/modules/file/file.module
index 1e98f11..eea5847 100644
--- a/modules/file/file.module
+++ b/modules/file/file.module
@@ -239,6 +239,9 @@ function file_ajax_upload() {
   $form_parents = func_get_args();
   $form_build_id = (string) array_pop($form_parents);
 
+  // Sanitize form parents before using them.
+  $form_parents = array_filter($form_parents, 'element_child');
+
   if (empty($_POST['form_build_id']) || $form_build_id != $_POST['form_build_id']) {
     // 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');