MDL-18229 gradebook: Sesskey required for all actions.

grade/report/singleview/classes/local/screen/tablelike.php

@@ -189,8 +189,11 @@ abstract class tablelike extends screen {
 
         $buttons = html_writer::tag('div', $buttonhtml, $buttonattr);
 
+        $sessionvalidation = html_writer::empty_tag('input',
+            array('type' => 'hidden', 'name' => 'sesskey', 'value' => sesskey()));
+
         return html_writer::tag('form',
-            $buttons . html_writer::table($table) . $this->bulk_insert() . $buttons,
+            $buttons . html_writer::table($table) . $this->bulk_insert() . $buttons . $sessionvalidation,
             array('method' => 'POST')
         );
     }

grade/report/singleview/index.php

@@ -99,6 +99,7 @@ $pageparams = array(
 $currentpage = new moodle_url('/grade/report/singleview/index.php', $pageparams);
 
 if ($data = data_submitted()) {
+    require_sesskey(); // Must have a sesskey for all actions.
     $warnings = $report->process_data($data);
 
     if (empty($warnings)) {