Commonly Hacked Ports

Common ports, such as HTTP (80), are likely well secured — but other ports may get overlooked and be vulnerable to hackers. In your ethical hacking tests, be sure to check these commonly hacked TCP and UDP ports:

• TCP port 21 - FTP (File Transfer Protocol)

  
  



• TCP port 23 - telnet

  
  



• TCP port 25 - SMTP (Simple Mail Transfer Protocol)

  
  



• TCP and UDP port 53 - DNS (Domain Name System)

  
  



• TCP ports 80 and 443 - HTTP (Hypertext Transport Protocol) and HTTPS (HTTP over SSL)

  
  



• TCP port 110 - POP3 (Post Office Protocol version 3)

  
  



• TCP and UDP port 135 - Windows RPC

  
  



• TCP and UDP ports 137–139 - Windows NetBIOS over TCP/IP

  
  

dummies

Source:http://www.dummies.com/how-to/content/commonly-hacked-ports.html