diff --git a/app/controllers/oer/addfile.php b/app/controllers/oer/addfile.php
index eb173410e50ff3a343a41c56bde4c41bde1d6147..77822b7daf2ebb1102d16eaf4164dc145bd39eb7 100644
--- a/app/controllers/oer/addfile.php
+++ b/app/controllers/oer/addfile.php
@@ -25,7 +25,8 @@ class Oer_AddfileController extends AuthenticatedController
             ];
             if ($material['host_id']) {
                 $tmp_name = $GLOBALS['TMP_PATH']."/oer_".$material->getId();
-                file_put_contents($tmp_name, file_get_contents($material->getDownloadUrl()));
+                $url = $material->getDownloadUrl();
+                file_put_contents($tmp_name, file_get_contents($url, false, get_default_http_stream_context($url)));
                 $uploaded_file['tmp_name'] = $tmp_name;
                 $uploaded_file['type'] = filesize($tmp_name);
             } else {
diff --git a/app/controllers/oer/endpoints.php b/app/controllers/oer/endpoints.php
index 5986e7d44b03ca45720a5b71913d9e8934b58420..448565dac2e2465172f5d6a8048774c7f62311c5 100644
--- a/app/controllers/oer/endpoints.php
+++ b/app/controllers/oer/endpoints.php
@@ -93,7 +93,8 @@ class Oer_EndpointsController extends StudipController
         if (!$host) {
             return;
         }
-        $host_data = file_get_contents($url."fetch_public_host_key");
+        $url = $url."fetch_public_host_key";
+        $host_data = @file_get_contents($url, false, get_default_http_stream_context($url));
         if ($host_data) {
             $host_data = json_decode($host_data, true);
             if ($host_data) {
diff --git a/lib/models/OERDownloadcounter.php b/lib/models/OERDownloadcounter.php
index fa603a380a5c170a8dd2b0fe3df79fade5bc9226..4e0a68779062d5097b219c0e3b5a5dea4fb78220 100644
--- a/lib/models/OERDownloadcounter.php
+++ b/lib/models/OERDownloadcounter.php
@@ -13,7 +13,9 @@ class OERDownloadcounter extends SimpleORMap
         $counter['material_id'] = $material_id;
         if (Config::get()->oer_GEOLOCATOR_API) {
             list($url, $lon, $lat) = explode(" ", Config::get()->oer_GEOLOCATOR_API);
-            $output = json_decode(file_get_contents(sprintf($url, $_SERVER['REMOTE_ADDR'])), true);
+            $url = sprintf($url, $_SERVER['REMOTE_ADDR']);
+            $output = @file_get_contents($url, false, get_default_http_stream_context($url));
+            $output = json_decode($output, true);
             if (isset($output[$lon])) {
                 $counter['longitude'] = $output[$lon];
             }
diff --git a/lib/models/OERHost.php b/lib/models/OERHost.php
index d0b1f6928a68fd0db5a5ae37e1929659679d232f..27de21a3aaf828cd368ee897b3a4e5028b36b21a 100644
--- a/lib/models/OERHost.php
+++ b/lib/models/OERHost.php
@@ -100,7 +100,7 @@ class OERHost extends OERIdentity
     {
         $endpoint_url = $this['url']."fetch_public_host_key";
         $endpoint_url .= "?from=".urlencode($GLOBALS['oer_PREFERRED_URI'] ?: $GLOBALS['ABSOLUTE_URI_STUDIP']."dispatch.php/oer/endpoints/");
-        $host_data = @file_get_contents($endpoint_url);
+        $host_data = @file_get_contents($endpoint_url, false, get_default_http_stream_context($endpoint_url));
         if ($host_data) {
             $host_data = json_decode($host_data, true);
             if ($host_data) {
@@ -124,7 +124,7 @@ class OERHost extends OERIdentity
     {
         $endpoint_url = $this['url']."fetch_known_hosts"
             ."?from=".urlencode(!empty($GLOBALS['oer_PREFERRED_URI']) ?: $GLOBALS['ABSOLUTE_URI_STUDIP']."dispatch.php/oer/endpoints/");
-        $output = @file_get_contents($endpoint_url);
+        $output = @file_get_contents($endpoint_url, false, get_default_http_stream_context($endpoint_url));
         if (!empty($output)) {
             $output = json_decode($output, true);
             foreach ((array) $output['hosts'] as $host_data) {
@@ -157,7 +157,7 @@ class OERHost extends OERIdentity
         } else {
             $endpoint_url .= "?text=".urlencode($text);
         }
-        $output = @file_get_contents($endpoint_url);
+        $output = @file_get_contents($endpoint_url, false, get_default_http_stream_context($endpoint_url));
         if ($output) {
             $output = json_decode($output, true);
             foreach ((array) $output['results'] as $material_data) {
@@ -241,7 +241,7 @@ class OERHost extends OERIdentity
     public function fetchItemData(OERMaterial $material)
     {
         $endpoint_url = $this['url']."get_item_data/".urlencode($material['foreign_material_id']);
-        $output = @file_get_contents($endpoint_url);
+        $output = @file_get_contents($endpoint_url, false, get_default_http_stream_context($endpoint_url));
         if ($output) {
             $output = json_decode($output, true);
             if ($output) {
diff --git a/lib/models/OERHostOERSI.php b/lib/models/OERHostOERSI.php
index f4b0c60a81783a33a82e8f0de1d874d0cbd0dd5e..750f374bd944b771dc97bc07b9691c2a8293f69e 100644
--- a/lib/models/OERHostOERSI.php
+++ b/lib/models/OERHostOERSI.php
@@ -17,7 +17,7 @@ class OERHostOERSI extends OERHost
         } else {
             $endpoint_url .= '?q=' . urlencode($text . $appendix);
         }
-        $output = @file_get_contents($endpoint_url);
+        $output = @file_get_contents($endpoint_url, false, get_default_http_stream_context($endpoint_url));
         if ($output) {
             $output = json_decode($output, true);
             foreach ((array) $output['hits']['hits'] as $material_data) {
@@ -88,7 +88,7 @@ class OERHostOERSI extends OERHost
     public function fetchItemData(OERMaterial $material)
     {
         $endpoint_url = 'https://oersi.de/resources/' . urlencode($material['data']['id']) . '?format=json';
-        $output = @file_get_contents($endpoint_url);
+        $output = @file_get_contents($endpoint_url, false, get_default_http_stream_context($endpoint_url));
         if ($output) {
             $output = json_decode($output, true);
             if ($output) {
diff --git a/lib/modules/CoreDocuments.class.php b/lib/modules/CoreDocuments.class.php
index 1382a37d0e01b17eba05e1dd4a958e1b5a7b9037..4543b8773de18ad60a3888b6e17e7855b2973d66 100644
--- a/lib/modules/CoreDocuments.class.php
+++ b/lib/modules/CoreDocuments.class.php
@@ -54,7 +54,7 @@ class CoreDocuments extends CorePlugin implements StudipModule, OERModule
         if ($url) {
             if ($material['host_id']) {
                 $tmp_name = $GLOBALS['TMP_PATH'] . '/oer_' . $material->getId();
-                file_put_contents($tmp_name, file_get_contents($url));
+                file_put_contents($tmp_name, file_get_contents($url, false, get_default_http_stream_context($url)));
                 $uploaded_file['tmp_name'] = $tmp_name;
                 $uploaded_file['type'] = filesize($tmp_name);
             } else {