What exactly is happening when a program or service is listening on a port?

[resettler 0]

I do not have much IT knowledge.

 

When I type netstats on Ubuntu 12.04 LTS inside a terminal window, I get to see a list of programs or services that are lisitening on ports.

 

Questions:

 

1. Does it mean that these programs or services are continually sending out packets of data?

 

2. Are those ports that are being "listened on" open?

[Staff 10334]

Hello!

 

1. No.

 

2. Not necessarily.

 

For clarifications and information, you can read a quite good article on Wikipedia:

http://en.wikipedia.org/wiki/Port_%28computer_networking%29

 

Kind regards

[resettler 0]

Thanks for your reply.

 

Suppose you use a VPN to connect to the internet and all programs are routed through it.

 

Can a rogue website send packets of geolocation inquiry to those services that listen on ports to find out your exact IP address, thereby bypassing your VPN?

[Staff 10334]

Hello!

 

A rogue web site might try to do that through the injection of malware via Flash, Java (not to be confused with javascript) or, if you run Internet Explorer, ActiveX; or through attempted execution of malicious Flash and Java code; or maybe through exploitation of some other vulnerable plug-in. If you browse to a web site you don't know well, the first, and strong, line of defense is preventing any script execution from the pages code. With Firefox a quick way to accomplish this is via NoScript.

http://noscript.net/

 

Kind regards

[resettler 0]

A rogue web site might try to do that through the injection of malware via Flash, Java (not to be confused with javascript) or, if you run Internet Explorer, ActiveX; or through attempted execution of malicious Flash and Java code; or maybe through exploitation of some other vulnerable plug-in. If you browse to a web site you don't know well, the first, and strong, line of defense is preventing any script execution from the pages code. With Firefox a quick way to accomplish this is via NoScript.

http://noscript.net/

 

Thanks for your reply.

 

With reference to both my question

 

 

Can a rogue website send packets of geolocation inquiry to those services that listen on ports to find out your exact IP address, thereby bypassing your VPN?

 

and your answer, the only way for a rogue website to bypass my VPN to find out my exact IP address is by tricking me into installing some Flash or Java add-on.

 

When one is using Linux such as Ubuntu or Debian, a rogue website can't just install malware or malicious code/script on the OS without having the user first typing in his password, am I right?