Re: cisco nac bypass vulnerability - cisco trust agent

[Stefano Zanero <s.zanero () securenetwork it>]

thorben schroeder wrote:

> the  cisco  network  admission control system gives an adminitrator the
> chance  to  check  the  clients,  whether  they have installed certain
> patches / hotfixes. this check is not reliable.

This is a known vulnerability of any system of NAC which trusts a client
based agent. Since you cannot determine what program is running on the
remote system, you cannot really trust what it is declaring.

So, nothing really new in what you reported (you could also reverse
engineer and write a client which answers the server exactly what it
wants to hear).

The point is knowing and accepting the unavoidable limits of such
technologies.

Stefano