Re: Port scan causing system crashes

From: Clem Skorupka (ragnorat_private)
Date: Thu Jun 12 2003 - 14:00:03 PDT

  • Next message: Brass, Phil (ISS Atlanta): "RE: Port scan causing system crashes"

    I should have added that this particular test was done in a lab setting ; ) .  In general, your scanning methodology should take into account the vagaries of a network's critical infrastructure, and arrangements should be made to have appropriate personnel available to fix what might break.  So don't go taking out all the switches at a remote site in the off hours.
    
    Now a nice thing would be to have your network/ops group include "ability to survive reasonable vulnerability scans" as part of their system requirements, and/or incorporate such probes in acceptance testing for production rollouts.  But in this vale of tears we take what we are sent ; )
    
    Clem Skorupka
    
    Renaud Deraison wrote:
    
    > On Thu, Jun 12, 2003 at 11:55:26AM -0400, Clem Skorupka wrote:
    >
    > > I had a case where an rpc scan using nessus (I forget the particular module or if it was the nmap precursor scan, this was a couple of years ago) against some large range of ports knocked out an allegro-based embedded web server on a network switch.  It didn't crash this particular switch (though one had to reboot the switch in order to bring back the web interface).
    >
    > The bottom line is that as soon as you start to interfere with another
    > host, you can never predict how it will react to actions that it has
    > never been designed to handle, so no scan is totally risk-free[1], and
    > it's often very hard to find the balance between a 99.9% accurate
    > security audit and a non-intrusive one. Note that this does not only
    > affects Nessus+Nmap, but any network vulnerability scanner.
    
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