[Full-Disclosure] Zone Alarm

[Larry W. Cashdollar]

On Fri, 13 Jun 2003, Stephane Nasdrovisky wrote:

>
> Squid (and probably others) can filter accesses based on the user agent.
> Some network firewall (as opposed to personal ones) can be configured to filter accesses based on the user agent header.
>
> As you know, every peace of software trying to access internet through a
>proxy advertise its flavour using the user agent header, and the user
>agent header is very hard to spoof :-)

I am guessing what you mean by software is web browser?
I can recompile mozilla/konqueror/lynx to say whatever I want as a
user-agent.  I think opera lets you masquerade as which ever browser you want
IE/netscape etc...  You can connect to an http server will telnet and do
a:

GET / HTTP/1.0
User-Agent:	Bubba-joe-Browser1.1a

see RFC 1945/2068 on the http protocol.

Why even bother putting in a User-Agent?  You dont have to.  If the server
is trusting the client for information, well you make the client give
whatever information you want if you have sufficent access to it.

-- La