I set up Serve-U In order for it to work I had to forward port 21 in my router settings. I just ran a firewall test and got the following message.
Type Port Services, Programs and Trojans that are commonly found to be running on this port.
tcp 21 This is the FTP service control port. Firewall rules focus on this port; then open port 20 only when required for a data transfer. Security Concerns with FTP: Cleartext; re-usable passwords. - Portal for user account grinding. - FTP Bounce; where attacker uses ftp's "port" command to redirect the FTP transfer to a port & IP other than default port 20 on the FTP server. Attacks can include "bouncing" internal network scans; email forging/flooding; etc. CERT Advisories: CA-97.16; CA-99.13. Disable this service on non-FTP servers. Open at perimeter only with static route to internal FTP server(s).
Trojans or Viruses known to use this port are: Back Construction. BladeRunner. Cattivik FTP Server. CC Invader. Dark FTP. Doly Trojan. Fore. FreddyK. Invisible FTP. Juggernaut 42. Larva. MotIv FTP. Net Administrator. Ramen. RTB 666. Senna Spy FTP server. The Flu. Traitor 21. WebEx. WinCrash.
Is it safe to leave this port open?
Edited by Andybikecrazy, 02 November 2005 - 07:04 PM.