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Skoll

Member

Registered: 2009-09-23

Posts: 36

[SOLVED] Firefox listens on localhost, random ports

I've opened a jpeg image today and while it was rendering, most of the characters became gibberish and artifacts appeared in every GUI even on tint2. I thought it could have been some kind of buffer overflow or the jpeg image had a code that could exploit vulnerabilities in Firefox so I checked my net activity.

I've found that Firefox is listening on localhost through random ports for any incoming traffic. In Net Activity Viewer it is shown as:
Protocol: TCP
Local Host: localhost
Local Address: 127.0.0.1
Local Port: random port usually higher than 40000
State: LISTEN
Remote Address: *
Remote Port: *
Remote Host: .
PID: pid number
Program: firefox
Command: firefox
Is this a normal behaviour or should I be worried?

Last edited by Skoll (2010-06-30 00:34:00)

kokoko3k

Member

Registered: 2008-11-14

Posts: 2,464

Re: [SOLVED] Firefox listens on localhost, random ports

I think you should ask mozilla devs after been able to reproduce the issue.
BTW, mine isn't listening to anything:

kokonicki@netbook ~ $ netstat -anpt|grep LISTENING|grep firefox
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
kokonicki@netbook ~ $

Last edited by kokoko3k (2010-06-29 09:11:40)

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Skoll

Member

Registered: 2009-09-23

Posts: 36

Re: [SOLVED] Firefox listens on localhost, random ports

Try netstat -anpt|grep LISTEN|grep firefox

stqn

Member

Registered: 2010-03-19

Posts: 1,191

Website

Re: [SOLVED] Firefox listens on localhost, random ports

Here, this command doesn't return anything for Firefox either.

hokasch

Member

Registered: 2007-09-23

Posts: 1,461

Re: [SOLVED] Firefox listens on localhost, random ports

Mine does the same, Skoll. Must be an extension, nothing with a new profile. Hmm.

P.S.:
I have 5001 opened by Zotero, and a random one > 4000 from GoogleSharing.

Also see
http://support.mozilla.com/en-US/kb/Fir … onnections

Last edited by hokasch (2010-06-29 22:43:46)

Skoll

Member

Registered: 2009-09-23

Posts: 36

Re: [SOLVED] Firefox listens on localhost, random ports

Thanks hokasch, I've realized now that I have Google Sharing installed too but noticed it too late because my status bar is hidden. So it means that extensions probably listens on that random picked port.

Now I have to find out why X created artifacts while that jpeg image was rendering.

Thanks again.

Last edited by Skoll (2010-06-30 00:36:22)