Mozilla will stop supporting FTP servers in Firefox. The company will disable the connection function on these servers from the upcoming version 77, which will be released on June 2, 2020.
From Firefox 77, the connection function to FTP servers will be disabled, but the interested user will be able to re-enable it by selecting network.ftp.enabled in the internal URL about: config. This will not affect ESR versions, where the connection to the FTP servers will remain functional until at least version 78.
For 2021, Mozilla plans to remove all FTP code from its browser for the following reasons:
- The FTP protocol is obsolete.
- The FTP code in the browser is also outdated and difficult to maintain in modern versions of the browser.
- FTP connections (not sFTP) are insecure in MITM (man-in-the-middle) attacks.
As you may remember that from him Firefox 61 Mozilla browser does not load FTP web resources, e.g. images, which have links from FTPs. Starting from the version Firefox 70, the browser does not render the files that are in FTP.
Likewise, Chrome 80 has FTP enabled, and the complete removal of FTP code in Chrome 82 will be coming soon.
According to Google statistics, only 0,1% of Chrome users use FTP.
Mozilla recommends using external applications for FTP tasks. Personally, I recommend it FileZilla project both for the FTP client but also for FTP servers.