See how ftpd compares to other vendors in security performance
FTP servers such as OpenBSD ftpd, NetBSD ftpd, ProFTPd and Opieftpd do not properly cleanse untrusted format strings that are used in the setproctitle function (sometimes called by setproctitle), which allows remote attackers to cause a denial of service or execute arbitrary commands.
ftpd, as used by Gentoo and Debian Linux, sets the gid to the effective uid instead of the effective group id before executing /bin/ls, which allows remote authenticated users to list arbitrary directories with the privileges of gid 0 and possibly enable additional attack vectors.