Re: Firewall hits/unknown ports

From: Valdis.Kletnieksat_private
Date: Sun Nov 04 2001 - 20:13:53 PST

  • Next message: freeholdat_private: "Re: Firewall hits/unknown ports"

    On Sun, 04 Nov 2001 21:28:29 CST, Glenn Forbes Fleming Larratt <glrattat_private>  said:
    > You might look at (and provide) what they're using for a "source" port -
    > I've seen numerous "reverse http" and "reverse telnet" scans, where
    > a source port of 80 or 23 is used. Such a approach could fool
    > a stateless firewall or IDS.
    > On Sun, 4 Nov 2001 bonkat_private wrote:
    > > Anyone know what trojans/backdoors run on 22634, 24544 and 29319 ?
    > > 22634		24.254.60.19		unknown		Nov  3 23:49:26
    
    Equally to the point - I may have blinked, but I didn't see ruled out
    that 24.254.60.19 isn't running a http/smtp/ftp/whatever server
    unbeknownst to the firewall admin.  So 22634 may be a totally
    reasonable ephemeral port picked at the client end for a connection to
    a web server running on the box, triggering an IDS.
    
    And remember that there's at least one instant messaging client that
    provides a baby web server onboard....
    
    				Valdis Kletnieks
    				Operating Systems Analyst
    				Virginia Tech
    
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