Subject: Nix that last message....

From: Phil Poole <[email-masked]>
Date: Tue, 9 Sep 1997 11:58:08 -0400 (EDT)

Ok,

	Nix..that last message...a single connect ran the load up to
	about 1.5 but stopped at that point.

	Multiple connects running this command will increase the load
	accordingly.  

	So I guess the Denial of Service is in the one of the
	following forms:

	1) Start up anonymous connects and run the ls command
	
	ls../*/../*/../*/../*/../*/../*/../*/../*/../*/../*/../*/../*/../
	*/../*/../*/../*/../*/../*/../*/../*/../*/../*/../*/../*/../*/../
	*/../*/../*/../*/../*/../*/../*/../*/../*/../*/../*/../*../*../*

	increasing the load to more then the system can handle.  Thus
	crashing the system.

	2) Attempt to crash the system with the "nlist" vulnerability
	   but simply occupy all of the available connections and
	   cause the system load to be extremely high.
	   (In the case that you are only offering a fewer FTP
	     connects then it would take to crash your system)
	 
	   These connections never appear to time-out since 
	   they are being processed.
	
	  On my system after a steep initial climb in load it
	  has evened out at 1.5 for each ftp connect running
	  the "nlist" vulnerability.

	This could get nasty.
--
       Phil Poole	| Unix Systems Administrator
     [email-masked]	| Frederick Biomedical SuperComputing Center
      (301) 846-5721	| Frederick MD, 21702