Vsftpd

vsftpd is an FTP server for Unix-like systems, including Linux. It is the default FTP server in the Ubuntu, CentOS, Fedora, NimbleX, Slackware and RHEL Linux distributions. It is licensed under the GNU [General Public License]. It supports IPv6, TLS and FTPS.

Compromised website

In July 2011, it was discovered that vsftpd version 2.3.4 downloadable from the master site had been compromised. 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. This was not an issue of a security hole in the original version of vsftpd; instead, an unknown attacker had uploaded a different version of vsftpd which contained a backdoor. Since then, the site was moved to Google [App Engine].