ProFTPD is a powerful, configurable, and free FTP daemon.
A flaw exists in the mod_ctrls module of ProFTPD, normally used to allow FTP server administrators to configure the daemon at runtime.
An FTP server administrator permitted to interact with mod_ctrls could potentially compromise the ProFTPD process and execute arbitrary code with the privileges of the FTP Daemon, which is normally the root user.
Disable mod_ctrls, or ensure only trusted users can access this feature.
All ProFTPD users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-ftp/proftpd-1.3.1_rc1"