diff --git a/mod/page/lib.php b/mod/page/lib.php
index 82d7725f542..d6fec761819 100644
--- a/mod/page/lib.php
+++ b/mod/page/lib.php
@@ -229,7 +229,7 @@ function page_get_coursemodule_info($coursemodule) {
     }
 
     $fullurl = "$CFG->wwwroot/mod/page/view.php?id=$coursemodule->id&inpopup=1";
-    $options = empty($page->displayoptions) ? array() : unserialize($page->displayoptions);
+    $options = empty($page->displayoptions) ? [] : (array) unserialize_array($page->displayoptions);
     $width  = empty($options['popupwidth'])  ? 620 : $options['popupwidth'];
     $height = empty($options['popupheight']) ? 450 : $options['popupheight'];
     $wh = "width=$width,height=$height,toolbar=no,location=no,menubar=no,copyhistory=no,status=no,directories=no,scrollbars=yes,resizable=yes";
diff --git a/mod/page/mod_form.php b/mod/page/mod_form.php
index ad87aec0beb..2052dffd667 100644
--- a/mod/page/mod_form.php
+++ b/mod/page/mod_form.php
@@ -130,7 +130,7 @@ class mod_page_mod_form extends moodleform_mod {
             $defaultvalues['page']['itemid'] = $draftitemid;
         }
         if (!empty($defaultvalues['displayoptions'])) {
-            $displayoptions = unserialize($defaultvalues['displayoptions']);
+            $displayoptions = (array) unserialize_array($defaultvalues['displayoptions']);
             if (isset($displayoptions['printintro'])) {
                 $defaultvalues['printintro'] = $displayoptions['printintro'];
             }
diff --git a/mod/page/view.php b/mod/page/view.php
index 1eefd2276e0..9251056c158 100644
--- a/mod/page/view.php
+++ b/mod/page/view.php
@@ -56,7 +56,7 @@ page_view($page, $course, $cm, $context);
 
 $PAGE->set_url('/mod/page/view.php', array('id' => $cm->id));
 
-$options = empty($page->displayoptions) ? array() : unserialize($page->displayoptions);
+$options = empty($page->displayoptions) ? [] : (array) unserialize_array($page->displayoptions);
 
 if ($inpopup and $page->display == RESOURCELIB_DISPLAY_POPUP) {
     $PAGE->set_pagelayout('popup');
diff --git a/mod/resource/lib.php b/mod/resource/lib.php
index f7d387911b0..6da4d0f0915 100644
--- a/mod/resource/lib.php
+++ b/mod/resource/lib.php
@@ -234,7 +234,7 @@ function resource_get_coursemodule_info($coursemodule) {
 
     if ($display == RESOURCELIB_DISPLAY_POPUP) {
         $fullurl = "$CFG->wwwroot/mod/resource/view.php?id=$coursemodule->id&redirect=1";
-        $options = empty($resource->displayoptions) ? array() : unserialize($resource->displayoptions);
+        $options = empty($resource->displayoptions) ? [] : (array) unserialize_array($resource->displayoptions);
         $width  = empty($options['popupwidth'])  ? 620 : $options['popupwidth'];
         $height = empty($options['popupheight']) ? 450 : $options['popupheight'];
         $wh = "width=$width,height=$height,toolbar=no,location=no,menubar=no,copyhistory=no,status=no,directories=no,scrollbars=yes,resizable=yes";
@@ -250,7 +250,7 @@ function resource_get_coursemodule_info($coursemodule) {
     // add some file details as well to be used later by resource_get_optional_details() without retriving.
     // Do not store filedetails if this is a reference - they will still need to be retrieved every time.
     if (($filedetails = resource_get_file_details($resource, $coursemodule)) && empty($filedetails['isref'])) {
-        $displayoptions = @unserialize($resource->displayoptions);
+        $displayoptions = (array) unserialize_array($resource->displayoptions);
         $displayoptions['filedetails'] = $filedetails;
         $info->customdata['displayoptions'] = serialize($displayoptions);
     } else {
diff --git a/mod/resource/locallib.php b/mod/resource/locallib.php
index fc9413a0e67..f90bcceca28 100644
--- a/mod/resource/locallib.php
+++ b/mod/resource/locallib.php
@@ -226,7 +226,7 @@ function resource_print_workaround($resource, $cm, $course, $file) {
         case RESOURCELIB_DISPLAY_POPUP:
             $path = '/'.$file->get_contextid().'/mod_resource/content/'.$resource->revision.$file->get_filepath().$file->get_filename();
             $fullurl = file_encode_url($CFG->wwwroot.'/pluginfile.php', $path, false);
-            $options = empty($resource->displayoptions) ? array() : unserialize($resource->displayoptions);
+            $options = empty($resource->displayoptions) ? [] : (array) unserialize_array($resource->displayoptions);
             $width  = empty($options['popupwidth'])  ? 620 : $options['popupwidth'];
             $height = empty($options['popupheight']) ? 450 : $options['popupheight'];
             $wh = "width=$width,height=$height,toolbar=no,location=no,menubar=no,copyhistory=no,status=no,directories=no,scrollbars=yes,resizable=yes";
@@ -292,7 +292,7 @@ function resource_print_heading($resource, $cm, $course, $notused = false) {
  * @return string Size and type or empty string if show options are not enabled
  */
 function resource_get_file_details($resource, $cm) {
-    $options = empty($resource->displayoptions) ? array() : @unserialize($resource->displayoptions);
+    $options = empty($resource->displayoptions) ? [] : (array) unserialize_array($resource->displayoptions);
     $filedetails = array();
     if (!empty($options['showsize']) || !empty($options['showtype']) || !empty($options['showdate'])) {
         $context = context_module::instance($cm->id);
@@ -361,7 +361,7 @@ function resource_get_optional_details($resource, $cm) {
 
     $details = '';
 
-    $options = empty($resource->displayoptions) ? array() : @unserialize($resource->displayoptions);
+    $options = empty($resource->displayoptions) ? [] : (array) unserialize_array($resource->displayoptions);
     if (!empty($options['showsize']) || !empty($options['showtype']) || !empty($options['showdate'])) {
         if (!array_key_exists('filedetails', $options)) {
             $filedetails = resource_get_file_details($resource, $cm);
@@ -422,7 +422,7 @@ function resource_get_optional_details($resource, $cm) {
 function resource_print_intro($resource, $cm, $course, $ignoresettings=false) {
     global $OUTPUT;
 
-    $options = empty($resource->displayoptions) ? array() : unserialize($resource->displayoptions);
+    $options = empty($resource->displayoptions) ? [] : (array) unserialize_array($resource->displayoptions);
 
     $extraintro = resource_get_optional_details($resource, $cm);
     if ($extraintro) {
diff --git a/mod/resource/mod_form.php b/mod/resource/mod_form.php
index 37f2c480f1d..0f1addfc00c 100644
--- a/mod/resource/mod_form.php
+++ b/mod/resource/mod_form.php
@@ -158,7 +158,7 @@ class mod_resource_mod_form extends moodleform_mod {
             $default_values['files'] = $draftitemid;
         }
         if (!empty($default_values['displayoptions'])) {
-            $displayoptions = unserialize($default_values['displayoptions']);
+            $displayoptions = (array) unserialize_array($default_values['displayoptions']);
             if (isset($displayoptions['printintro'])) {
                 $default_values['printintro'] = $displayoptions['printintro'];
             }
diff --git a/mod/url/lib.php b/mod/url/lib.php
index 2ef5f3385dc..fa654073697 100644
--- a/mod/url/lib.php
+++ b/mod/url/lib.php
@@ -226,7 +226,7 @@ function url_get_coursemodule_info($coursemodule) {
 
     if ($display == RESOURCELIB_DISPLAY_POPUP) {
         $fullurl = "$CFG->wwwroot/mod/url/view.php?id=$coursemodule->id&redirect=1";
-        $options = empty($url->displayoptions) ? array() : unserialize($url->displayoptions);
+        $options = empty($url->displayoptions) ? [] : (array) unserialize_array($url->displayoptions);
         $width  = empty($options['popupwidth'])  ? 620 : $options['popupwidth'];
         $height = empty($options['popupheight']) ? 450 : $options['popupheight'];
         $wh = "width=$width,height=$height,toolbar=no,location=no,menubar=no,copyhistory=no,status=no,directories=no,scrollbars=yes,resizable=yes";
diff --git a/mod/url/locallib.php b/mod/url/locallib.php
index 05170b106e1..00240f48e13 100644
--- a/mod/url/locallib.php
+++ b/mod/url/locallib.php
@@ -83,7 +83,7 @@ function url_fix_submitted_url($url) {
  */
 function url_get_full_url($url, $cm, $course, $config=null) {
 
-    $parameters = empty($url->parameters) ? array() : unserialize($url->parameters);
+    $parameters = empty($url->parameters) ? [] : (array) unserialize_array($url->parameters);
 
     // make sure there are no encoded entities, it is ok to do this twice
     $fullurl = html_entity_decode($url->externalurl, ENT_QUOTES, 'UTF-8');
@@ -195,7 +195,7 @@ function url_print_heading($url, $cm, $course, $notused = false) {
 function url_print_intro($url, $cm, $course, $ignoresettings=false) {
     global $OUTPUT;
 
-    $options = empty($url->displayoptions) ? array() : unserialize($url->displayoptions);
+    $options = empty($url->displayoptions) ? [] : (array) unserialize_array($url->displayoptions);
     if ($ignoresettings or !empty($options['printintro'])) {
         if (trim(strip_tags($url->intro))) {
             echo $OUTPUT->box_start('mod_introbox', 'urlintro');
@@ -284,7 +284,7 @@ function url_print_workaround($url, $cm, $course) {
     $display = url_get_final_display_type($url);
     if ($display == RESOURCELIB_DISPLAY_POPUP) {
         $jsfullurl = addslashes_js($fullurl);
-        $options = empty($url->displayoptions) ? array() : unserialize($url->displayoptions);
+        $options = empty($url->displayoptions) ? [] : (array) unserialize_array($url->displayoptions);
         $width  = empty($options['popupwidth'])  ? 620 : $options['popupwidth'];
         $height = empty($options['popupheight']) ? 450 : $options['popupheight'];
         $wh = "width=$width,height=$height,toolbar=no,location=no,menubar=no,copyhistory=no,status=no,directories=no,scrollbars=yes,resizable=yes";
diff --git a/mod/url/mod_form.php b/mod/url/mod_form.php
index 2328ccae4af..eb3d2d0a191 100644
--- a/mod/url/mod_form.php
+++ b/mod/url/mod_form.php
@@ -105,7 +105,7 @@ class mod_url_mod_form extends moodleform_mod {
         if (empty($this->current->parameters)) {
             $parcount = 5;
         } else {
-            $parcount = 5 + count(unserialize($this->current->parameters));
+            $parcount = 5 + count((array) unserialize_array($this->current->parameters));
             $parcount = ($parcount > 100) ? 100 : $parcount;
         }
         $options = url_get_variable_options($config);
@@ -131,7 +131,7 @@ class mod_url_mod_form extends moodleform_mod {
 
     function data_preprocessing(&$default_values) {
         if (!empty($default_values['displayoptions'])) {
-            $displayoptions = unserialize($default_values['displayoptions']);
+            $displayoptions = (array) unserialize_array($default_values['displayoptions']);
             if (isset($displayoptions['printintro'])) {
                 $default_values['printintro'] = $displayoptions['printintro'];
             }
@@ -143,7 +143,7 @@ class mod_url_mod_form extends moodleform_mod {
             }
         }
         if (!empty($default_values['parameters'])) {
-            $parameters = unserialize($default_values['parameters']);
+            $parameters = (array) unserialize_array($default_values['parameters']);
             $i = 0;
             foreach ($parameters as $parameter=>$variable) {
                 $default_values['parameter_'.$i] = $parameter;