diff --git a/src/app/qtsingleapplication/qtlocalpeer.cpp b/src/app/qtsingleapplication/qtlocalpeer.cpp
index f3c4546b6..d8a1bce31 100644
--- a/src/app/qtsingleapplication/qtlocalpeer.cpp
+++ b/src/app/qtsingleapplication/qtlocalpeer.cpp
@@ -101,6 +101,7 @@ QtLocalPeer::QtLocalPeer(QObject* parent, const QString &appId)
 #endif
 
     server = new QLocalServer(this);
+    server->setSocketOptions(QLocalServer::UserAccessOption);
     QString lockName = QDir(QDir::tempPath()).absolutePath()
                        + QLatin1Char('/') + socketName
                        + QLatin1String("-lockfile");
@@ -191,6 +192,12 @@ void QtLocalPeer::receiveConnection()
     QByteArray uMsg;
     quint32 remaining;
     ds >> remaining;
+    if (remaining > 65535) {
+        // drop suspiciously large data
+        delete socket;
+        return;
+    }
+
     uMsg.resize(remaining);
     int got = 0;
     char* uMsgBuf = uMsg.data();