This is predictable in an insecure product. I'm not
trying to act as if I discovered something new or Earth
shattering, but I am quite surprised there is nothing in
place in ASP.Net to protect user sessions from being
hijacked. It seems to me that the session IDs have been
problematic since ASP first came about. In ASP.Net they
are still for some reason handed out in a fashion that
means the same ID could be sent out to the same browser
even after a Session.Abandon(). It doesn't make sense
that Microsoft couldn't do something as simple as encrypt
the user agent and source IP into the session GUID if the
user wanted to lock the source and device of a request
down to a particular computer/network. From an
architectural standpoint I realize that this in itself
would add some overhead to IIS because every HTTP request
would have to be checked against a lookup, but with HTTP
keep-alives this check would only need to occur once on
the same connection. I also realize that someone could
use this to DoS a server by sending lots of HTTP requests
with random IDs that would have to decoded and matched up
against connections, but I'm sure that intrusion
detection systems could be made to deal with this issue.
The other option of course is to not use cookieless
sessions under the anonymous user configuration and rely
on an in-memory cookie which is obviously a little less
accessible. In either situation though, this seems like
an incredible option to not provide ASP users.
-----Original Message-----
It seems to me that this would be listed as a
predictable downside to usingcookieless sessions. Verifying IPs and/or user agents
wouldn't be any realway to avoid this, so it makes sense to me that this
wouldn't be the defaultbehavior for asp.net to check that. And if it were to
check it, where wouldit store this info? In session variables? Hmmph.
--
Ray at home
Microsoft ASP MVP
"Keith" <ke***@keithadler.com> wrote in message
news:77****************************@phx.gbl... I have found what I believe to be a serious security
issue in ASP.Net. If you have:
1. Your website configured for anonymous access
2. Elect under web.config to set the sessionstate
attribute of cookieless to true
Anyone from any IP address or across another browser
can copy the URL and work within the session. My question
is "Why doesn't ASP.Net provide an option around
ensuring all requests for a user session originate from the same
IP address and/or same useragent?" I know that some
people sit behind firewalls, proxies and layer 4
devices that could load balance and affect HTTP traffic, but it
honestly escapes me why I can access my web application
on any machine inside or outside of my network with
just the sessionid in the URL from even different browsers.
There must be a way to control this in the
configuration. Am I alone in find this troubling?
.