desabilitando servicos

passei um nmap no meu pc e os resultados foram:

Starting nmap V. 3.00 ( www.insecure.org/nmap/ )
Interesting ports on localhost (xxx.xxx.xxx):
(The 1591 ports scanned but not shown below are in state: closed)
Port State Service
21/tcp open ftp
22/tcp open ssh
25/tcp open smtp
37/tcp open time
79/tcp open finger
111/tcp open sunrpc
113/tcp open auth
515/tcp open printer
587/tcp open submission
6000/tcp open X11
Remote operating system guess: Linux Kernel 2.4.0 - 2.5.20
Uptime 0.022 days (since Mon Jul 14 18:14:16 2003)

Nmap run completed -- 1 IP address (1 host up) scanned in 6 seconds


essas portas open, significam algum risco de seguranca?