Mozilla Adopted a solution Remove from Firefox built-in implementation of the FTP protocol. In the release of Firefox 88, scheduled for April 19, the FTP support will be disabled by default (including the BROWSERSETTINGS.FTPPROTocolenabled configuration will be translated into read-only mode), and in the release of Firefox 90, scheduled for June 29, the code associated with FTP. When you try to open references with the “ftp: //” protocol identifier, the browser will cause an external application by analogy with how “IRC: //” and “TG: //” handlers are called.
As the reason for the termination of support for FTP is called The vitality of this protocol from modification and Interception of transit traffic when making MITM attacks. According to Firefox developers, in modern conditions there is no reason to use FTP instead of HTTPS to load resources. In addition, the FTP support code in Firefox is very old, creates problems with accompanied and has a history of detecting a large number of vulnerabilities in the past.
Recall that earlier in Firefox 61, downloading resources via the FTP protocol from the pages opened by http / https, and the Firefox 70 refrespens to draw the contents of files downloaded via FTP (for example, when opening via FTP has ceased to display images , Readme and HTML files, and immediately began to show the file download dialog to disk). In Chrome, FTP supports terminated in the January issue of Chrome 88. According to Google, the FTP is almost not used – the share of FTP users is about 0.1%.