Headline
Firefox 117 Denial Of Service
Firefox version 117 suffers from a file creation denial of service vulnerability.
This is barely a DoS, but since Chrome has explicit protectionagainst it, we decided to disclose it.If firefox user visits a specially crafted page, then firefoxmay create many files in `~/Downloads`,The user is notified about this in a small dialog, but there isno option to stop the downloads.The potential denial of service is that the user must manuallydelete the created files and this might be PITA.Technically about the PoC: create non-empty file `xml.doc`.To force download, add to the page `iframe src="xml.doc"`.To force creation of new files, add `body onload="location.reload()"`(there are several other options about this).[Proof of concept][1]To out surprise, Chrome is safe from this and it distinguishesmanual download from automated download and this might be becauseit is aware about this DoS.Affected: firefox 117 on GNU/Linux and reportedly on Windows.Not Affected: firefox on android, Chrome, lynx.[1]: https://j.ludost.net/y3.html--- poc y3.html ---<html><body>Wait about 20 seconds andcheck for new files in ~/Downloads and also for message from firefox. Written by Georgi Guninski.<iframe src="xml.doc" width=10 height=10></iframe><script>setInterval(function () {location.reload()},1000);</script></body></html>--- poc y3.html ---