fix: add security headers to nginx config (VAPT findings #3, #4)

Author: wicky-zipstack

frontend/nginx.conf

@@ -50,6 +50,12 @@ http {
         root  /usr/share/nginx/html;
         include /etc/nginx/mime.types;
 
+        # Security headers
+        add_header X-Frame-Options "DENY" always;
+        add_header X-Content-Type-Options "nosniff" always;
+        add_header Referrer-Policy "strict-origin-when-cross-origin" always;
+        add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:; connect-src 'self' https://*.visitran.com wss://*.visitran.com; object-src 'none'; base-uri 'self'; frame-ancestors 'none';" always;
+
         # If a react app URI is directly accessed we will get 404
         # since there will be no file representing that path.
         # Below config will load index.html file in such case and