Re: Multiple Spoofed HTTP Requests

[Jayson Anderson <sonick () sonick com>]

Greetings,

It is not possible to craft a -valid- HTTP request due to the Layer4
setup requirements (handshake) prior to the Layer7 request (HTTP
GET/etc.) Per spec, the OSI model must be traversed, not
randomly-accessed. It IS possible to craft the HTTP request in the
initial SYN request, but there isn't a server on earth that will be so
far out of spec that it would actually honor it. About the only chance
would be a v.01Alpha Jr. coder's 'My first httpd'. The only other
possibility is a specific application or proxy/wrapper that is designed
to accept and parse requests which contain an HTTP request in the SYN
packet payload; perhaps for obfuscated data transfer or stealing data...
I've never seen such a thing but would not be surprised if it exists due
to tcp/80 outbound prevalence.  Another IP exception could be
multicast...... 

It's still remotely possible that HTTP found in the SYN payload would
significantly CONFUSE a less-mature server software, but NOT likely.
Even in the incredibly remote chance some software parsed the SYN
payload and gave 2-whats about it, you still won't be able to see the
reply, if any. As you're probably already aware, the only thing this
would show any potential for is anonymously placing a small bit(s) of
data into memory or to disk, or (more likely) for DoS. But you knew that
already :) 

You can forge such a request but the odds of finding a host that cares
about the payload even enough to waste memory err'ing out the payloads
is worse than the odds of getting hit my lightning. 

Best Regards,
Jayson


On Fri, 2005-09-02 at 13:11 +0000, kuffya () gmail com wrote:
> Hi list, 
> I've used a variety of tools such as Nemesis, Packet Xcalibur & Libnet GUI to craft customized packets. Using such 
> tools, you can create packets at layers 2 up to 5 possibly spoofing your source IP, port numbers or whatever you see 
> fit. 
> The question is : Would it be possible to craft a HTTP request(or multiple requests) using a spoofed IP address? I'm 
> inclined to consider that it's not, the reason being you must have a 3-way handshake established before you can start 
> talking application layer protocols (such as HTTP). If you use a spoofed IP address, then there's no way of doing 
> that. On the other hand, I might be totally wrong, that's why I'm asking the list, for the list is wise. 
> If, however, it is possible could you please give me some directions on how to do it? 
>
> Thanks a lot
> S.
>
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website. Up to 75% of cyber attacks are launched on shopping carts, forms, 
login pages, dynamic content etc. Firewalls, SSL and locked-down servers are 
futile against web application hacking. Check your website for vulnerabilities 
to SQL injection, Cross site scripting and other web attacks before hackers do! 
Download Trial at:

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