fix: security issue fixed by not assigning download blob url to button, instead create a html element and auto click it for download

backend/server.ts

@@ -6,7 +6,12 @@ import { colorConvert } from "./src/routes/colorconvert.route";
 
 const app = Fastify({ logger: true });
 
-app.register(cors, { origin: "*", exposedHeaders: 'Content-Disposition' });
+app.register(cors, {
+  origin: "*",
+  exposedHeaders: "Content-Disposition",
+  methods: "POST",
+  allowedHeaders: "Content-Type",
+});
 app.register(multipart);
 app.register(libreConvert);
 app.register(colorConvert);

backend/src/routes/libreconvert.route.ts

@@ -69,6 +69,7 @@ export async function libreConvert(app: FastifyInstance) {
             "Content-Disposition",
             `attachment; filename="converted${outputFileExt}"`,
           )
+          .status(200)
           .send(convertedBuffer);
       } catch (error) {
         console.error("Convert error:", error);

frontend/src/app/doc-converter/page.tsx

@@ -3,14 +3,12 @@ import React, { useState } from "react";
 import Navbar from "../../components/Navbar";
 import Footer from "../../components/Footer";
 import Button from "../../components/Button";
-import Link from "next/link";
 import { ChevronDown, ChevronUp } from "lucide-react";
 import Dropdown from "@/components/Dropdown";
 import { FileFormatsTable, outputFileFormats } from "@/constants";
 
 export default function DocConverter() {
   const [file, setFile] = useState<File | null>(null);
-  const [downloadUrl, setDownloadUrl] = useState<string>("");
   const [loading, setLoading] = useState(false);
   const [tableOpen, setTableOpen] = useState(false);
   const [filteredOptions, setFilteredOptions] = useState<string[]>([]);
@@ -36,7 +34,6 @@ export default function DocConverter() {
       }
 
       setFile(selectedFile);
-      setDownloadUrl("");
       setSelectedOutputFormat("");
 
       const matchedFormat = outputFileFormats.find((format) =>
@@ -68,15 +65,26 @@ export default function DocConverter() {
       );
 
       if (!response.ok) {
-        return new Error(`Error: ${response.statusText}`);
+        console.error(`Error: ${response.statusText}`);
       }
 
       const blob = await response.blob();
       const url = window.URL.createObjectURL(blob);
-      setDownloadUrl(url);
+      const filename = file.name.split(".")[0];
+
+      const a = document.createElement("a");
+      a.href = url;
+      a.download = `${filename}${selectedOutputFormat}`;
+      document.body.appendChild(a);
+      a.click();
+      document.body.removeChild(a);
+
+      setTimeout(() => {
+        URL.revokeObjectURL(url);
+      }, 5000);
     } catch (error) {
       console.error("Error while converting:", error);
-      alert("Error while converting");
+      alert("Error while converting!");
     } finally {
       setLoading(false);
     }
@@ -109,11 +117,6 @@ export default function DocConverter() {
           />
         </div>
         <div className={"flex flex-row items-center gap-4 mt-4 mb-16"}>
-          {downloadUrl ? (
-            <Link id="downloadPDF" href={downloadUrl}>
-              <Button content="download" />
-            </Link>
-          ) : (
           <Button
             content={
               loading ? (
@@ -124,7 +127,6 @@ export default function DocConverter() {
             }
             onClick={convertDoc}
           />
-          )}
         </div>
         <div className="overflow-hidden text-xl rounded-lg border border-white mb-16 transition-all duration-300 ease-in-out hover:border-blue-400">
           <div