RE: Authentication Vulnerability in NetScreen ScreenOS

[Hugo van der Kooij <hvdkooij () vanderkooij org>]

On Thu, 26 Jun 2003, Brian Soby wrote:

> > However, after a user is authenticated, anyone else may also access the 
> > protected services if they orginate from the same source IP address (NAT'd 
> > network). The authentication mechanism is designed to authenticate based on 
> > source-ip address only.
>
> Most firewalls track authenticated users based on the client's source IP 
> address.  If you need a stronger method, you could always use the Netscreen 
> Remote client software and require a secure tunnel from the clients to get 
> to your protected resources.

The Check Point firewall has the option to do client authentication which 
is a lot of fun if you happen to hide a full class B network behind a 
single address.

It is not a security breach in the sense that the software is doing 
something inappropriate. The security breach is in the mind of the person 
thinking that IP addresses can be trusted for security purposes.

Hugo.

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