diff --git a/tfmsaview/static/server.js b/tfmsaview/static/server.js
index 091981f..58f9751 100755
--- a/tfmsaview/static/server.js
+++ b/tfmsaview/static/server.js
@@ -6,6 +6,11 @@ var http = require("http"),
 
 http.createServer(function(request, response) {
 
+    if (path.normalize(decodeURI(request.url)) !== decodeURI(request.url)) {
+        response.statusCode = 403;
+        response.end();
+        return;
+    }
   var uri = url.parse(request.url).pathname
     , filename = path.join(process.cwd(), uri);