diff --git a/lib/defaults.js b/lib/defaults.js
index f43253ccb..3f1ac0bda 100644
--- a/lib/defaults.js
+++ b/lib/defaults.js
@@ -18,7 +18,7 @@ Default.commonCSP = function (domain, sandbox) {
          */
         "child-src 'self' blob: " + domain + sandbox,
         // IE/Edge
-        "frame-src 'self' blob: " + domain + sandbox,
+        `frame-src 'self' blob:${sandbox}/* blob:${domain}/* ${domain} ${sandbox}`,
 
         /*  this allows connections over secure or insecure websockets
             if you are deploying to production, you'll probably want to remove
diff --git a/www/common/onlyoffice/inner.js b/www/common/onlyoffice/inner.js
index 041ddd685..547ef6c9d 100644
--- a/www/common/onlyoffice/inner.js
+++ b/www/common/onlyoffice/inner.js
@@ -1361,7 +1361,7 @@ define([
                 msgEv.fire(msg);
             });
             var postMsg = function (data) {
-                iframe.postMessage(data, '*');
+                iframe.postMessage(data, ApiConfig.httpSafeOrigin);
             };
             Channel.create(msgEv, postMsg, function (chan) {
                 APP.chan = chan;
diff --git a/www/common/outer/worker-channel.js b/www/common/outer/worker-channel.js
index 06b38a96b..73d0327da 100644
--- a/www/common/outer/worker-channel.js
+++ b/www/common/outer/worker-channel.js
@@ -1,8 +1,9 @@
 // This file provides the API for the channel for talking to and from the sandbox iframe.
 define([
     //'/common/sframe-protocol.js',
-    '/common/common-util.js'
-], function (/*SFrameProtocol,*/ Util) {
+    '/common/common-util.js',
+    '/api/config',
+], function (/*SFrameProtocol,*/ Util, ApiConfig) {
 
     var mkTxid = function () {
         return Math.random().toString(16).replace('0.', '') + Math.random().toString(16).replace('0.', '');
@@ -156,9 +157,17 @@ define([
             });
         };
 
+        var trusted = [
+            ApiConfig.httpUnsafeOrigin,
+            ApiConfig.httpSafeOrigin,
+            '', // sharedworkers
+        ];
+
         onMsg.reg(function (msg) {
             if (!chanLoaded) { return; }
             if (!msg.data || msg.data === '_READY') { return; }
+            if (!trusted.includes(msg.origin)) { return; }
+
             var data = typeof(msg.data) === "object" ? msg.data : JSON.parse(msg.data);
             if (typeof(data.ack) !== "undefined") {
                 if (acks[data.txid]) { acks[data.txid](!data.ack); }
diff --git a/www/common/sframe-common-outer.js b/www/common/sframe-common-outer.js
index a86eac425..7351a2485 100644
--- a/www/common/sframe-common-outer.js
+++ b/www/common/sframe-common-outer.js
@@ -170,7 +170,7 @@ define([
                 var iframe = $('#sbox-iframe')[0].contentWindow;
                 var postMsg = function (data) {
                     try {
-                        iframe.postMessage(data, '*');
+                        iframe.postMessage(data, ApiConfig.httpSafeOrigin || window.location.origin);
                     } catch (err) {
                         console.error(err, data);
                         if (data && data.error && data.error instanceof Error) {
diff --git a/www/common/sframe-common.js b/www/common/sframe-common.js
index 5ec215df5..8f97ba265 100644
--- a/www/common/sframe-common.js
+++ b/www/common/sframe-common.js
@@ -762,7 +762,7 @@ define([
                 msgEv.fire(msg);
             });
             var postMsg = function (data) {
-                iframe.postMessage(data, '*');
+                iframe.postMessage(data, ApiConfig.httpUnsafeOrigin);
             };
             SFrameChannel.create(msgEv, postMsg, waitFor(function (sfc) { ctx.sframeChan = sfc; }));
         }).nThen(function (waitFor) {
diff --git a/www/secureiframe/main.js b/www/secureiframe/main.js
index 7f88ff79e..8c33a2ff1 100644
--- a/www/secureiframe/main.js
+++ b/www/secureiframe/main.js
@@ -57,7 +57,7 @@ define([
                 var msgEv = Utils.Util.mkEvent();
                 var iframe = $('#sbox-secure-iframe')[0].contentWindow;
                 var postMsg = function (data) {
-                    iframe.postMessage(data, '*');
+                    iframe.postMessage(data, ApiConfig.httpSafeOrigin);
                 };
                 var w = waitFor();
                 var whenReady = function (msg) {
diff --git a/www/unsafeiframe/main.js b/www/unsafeiframe/main.js
index 603133f12..afc6553b7 100644
--- a/www/unsafeiframe/main.js
+++ b/www/unsafeiframe/main.js
@@ -60,7 +60,7 @@ define([
                 var msgEv = Utils.Util.mkEvent();
                 var iframe = $('#sbox-unsafe-iframe')[0].contentWindow;
                 var postMsg = function (data) {
-                    iframe.postMessage(data, '*');
+                    iframe.postMessage(data, ApiConfig.httpUnsafeOrigin);
                 };
                 var w = waitFor();
                 var whenReady = function (msg) {