fix: server crashes when receiving file download request with invalid byte range; this fixes a security vulnerability that allows an attacker to impact the availability of the server instance; the fix improves parsing of the range parameter to properly handle invalid range requests ([GHSA-h423-w6qv-2wj3](https://github.com/parse-community/parse-server/security/advisories/GHSA-h423-w6qv-2wj3)) [skip release] (#8237)

src/Routers/FilesRouter.js

@@ -266,5 +266,10 @@ export class FilesRouter {
 }
 
 function isFileStreamable(req, filesController) {
-  return req.get('Range') && typeof filesController.adapter.handleFileStream === 'function';
+  const range = (req.get('Range') || '/-/').split('-');
+  const start = Number(range[0]);
+  const end = Number(range[1]);
+  return (
+    (!isNaN(start) || !isNaN(end)) && typeof filesController.adapter.handleFileStream === 'function'
+  );
 }