It is the default FTP server in the Ubuntu, CentOS, Fedora, NimbleX, Slackware and RHEL Linux distributions.
It supports IPv6, TLS and FTPS (explicit since 2.0.0 and implicit since 2.1.0).
In July 2011, it was discovered that vsftpd version 2.3.4 downloadable from the master site had been compromised.
[2][3] Users logging into a compromised vsftpd-2.3.4 server may issue a ":)" smileyface as the username and gain a command shell on port 6200.
Since then, the site was moved to Google App Engine.