July 24, 2005

Defeating Firewalls: Sneaking Into Office Computers From Home

How-to Get Into Your Office Computer From Home (..without using VPN)
Greetings,

Ok guys. Last paper went well. Here is the new paper from me. This paper shows how easily you can ridicule the firewalls of your company.

In this paper, I discuss a technique to get into your office computer using ssh tunneling and some other cool tricks. You don't need anything much to implement this, not even an open port on the firewall. All you need from your company is the http(s) proxy which most of the companies do provide.


Here is the problem scenario - "You work with a company 'XYZ'. At office, you cannot access internet directly and you 'browse' internet using HTTP(S) proxy. Back at home, you have an internet connection. You want to access the office computer from home, but you don't have the VPN access." How do you do that? Read the paper for the solution.

Disclaimer: Please use your brain before using this technique. You can be kicked out by your employer for using it. Don't blame me.

Here are the links to the paper:

infosecwriters.com:
http://www.infosecwriters.com/text_resources/pdf/ssh_tunneling.pdf
googlepages.com:
http://articles.manugarg.com/ssh_tunneling.pdf

Let me know what you think about this paper.

cheers,
~manu
---------
Manu Garg
http://www.manugarg.com

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11 comments:

  1. Links are dead

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  2. I just checked again after removing my browser's cache. Links are working fine.

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  3. Nice How-To, Manu.

    Because of two things, it will not work for me.
    1- My company only allows port 80 (HTTP) and port 443 (SSL).
    2- I run a web server at home and use SSL for secure email access from the office, and for some other sites on my web server.

    It would be nice to see a module for Apache or IIS that would separate typical HTTP-over-SSL traffic from tunneling traffic so I could have the best of both worlds!

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  4. Try chownat out, it's a very interesting tool.

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  5. The links don't work for me either:

    HTTP Server Error 503
    No available server to handle this request

    ReplyDelete
  6. Guys, freezope.org seems to be down. Until that server comes back, you can download pdf from following location:

    http://manugarg.spymac.com/notes/ssh_tunneling.pdf

    ReplyDelete
  7. manu u reminded me of college days in IITK when only http n https was open..
    Had to work a lot even to download music n movies :D

    nice article

    HAIL OPEN SOURCE

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  8. Yes. This is what it used to be like in college days. Most of the companies still give only http/https access to internet.

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  9. Manu, is it possible to forward port 80 while the httpd service is running? I can only do local forwarding to port 80 and not from port 80.

    ReplyDelete
  10. <a href="http://phentermine1.eamped.com">Phentermine</a>19/8/07 5:11 AM

    This comment has been removed by a blog administrator.

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