[Snort-users] Snort on web servers behind reverse proxies
TPanaitescu at ...2032...
Thu May 1 11:34:39 EDT 2008
In my scenario the proxies are reverse proxies, they are not inside my
network and I am not worried about my internal IP addresses leaking out.
All parts are outside facing the world wide wild Internet, the clients
(one of them could be you :-) ) come to my web server through a bunch of
reverse proxies forwarding requests to my actual web servers, something
like this: Client -> Reverse Proxy -> Web server. On the web server, the
only thing I see in terms of IP addresses is just the IP addresses of the
reverse proxy and NOT the client's IP address. The only info of the
originating IP address (client's IP address) comes via the headers added by
the reverse proxies, as I mentioned in my previous email.
For your scenario, given that you use squid, just disable the
X-forwarded-for, walk in the park
Hope this clarifies the scenario.
<joel.esler at ...14350...
05/01/2008 11:25 <TPanaitescu at ...2032...>
snort-users at lists.sourceforge.net
Re: [Snort-users] Snort on web
servers behind reverse proxies
Okay, Let me clarify and you tell me if I am wrong or right. You want
to write a Snort rule to detect if your proxies are sending your
inside ip's out to the internet? Or are you asking how to modify your
proxies so that they don't send the IP's at all?
On May 1, 2008, at 10:29 AM, Tudor Panaitescu wrote:
> First of all I did some research and couldn't find anything about
> this, so
> no flames please :-)
> Here is the story. We have some reverse proxies/application
> accelerators/etc. (let's call them reverse proxies for now) in front
> of our
> web site. We don't control these reverse proxies and I am not sure
> if the
> provider has any IDS capabilities on those. I have snort (126.96.36.199)
> installed on the actual web servers but the only thing that I see in
> alerts is the IP addresses of the reverse proxies, which is normal.
> the reverse proxies, in their http requests to the web servers, they
> add 2
> entries in the headers: X-Forwarded-For: <origin's IP address> and
> True-Client-IP: <origin's IP address>. Is it a way to modify the
> rules to
> alert using any of these IP addresses instead of the IP address(es)
> of the
> reverse proxies ?
> Any help/idea would be appreciated.
> Thanks and all the best,
> Visit us at http://www.colorcon.com
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Joel Esler joel.esler at ...1935...
Visit us at http://www.colorcon.com
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