oftpd DoS vulnerability

Background

Quote from http://www.time-travellers .org/oftpd/

“oftpd is designed to be as secure as an anonymous FTP server can possibly be. It runs as non-root for most of the time, and uses the Unix chroot() command to hide most of the systems directories from external users - they cannot change into them even if the server is totally compromised! It contains its own directory change code, so that it can run efficiently as a threaded server, and its own directory listing code (most FTP servers execute the system “ls” command to list files).”

Description

Issuing a port command with a number higher than 255 causes the server to crash. The port command may be issued before any authentication takes place, meaning the attacker does not need to know a valid username and password in order to exploit this vulnerability.

Impact

This exploit causes a denial of service.

Workaround

While a workaround is not currently known for this issue, all users are advised to upgrade to the latest version of the affected package.

Resolution

All users should upgrade to the current version of the affected package:

 # emerge sync
 
 # emerge -pv ">=net-ftp/oftpd-0.3.7"
 # emerge ">=net-ftp/oftpd-0.3.7"