Subst.exe carelessness (fwd)

From: Ben Greenbaum (bgreenbaumat_private)
Date: Tue Nov 30 1999 - 16:07:01 PST

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    This was sent to vuldbat_private and is a good workaround for the
    subst problem posted here earlier. I repost it to the list with the
    author's permission. Thanks David!
    
    Ben Greenbaum
    Site Content Manager
    Security Focus
    http://www.securityfocus.com
    
    
    ---------- Forwarded message ----------
    Date: Tue, 30 Nov 1999 16:18:38 -0500
    From: dmandersat_private
    To: vuldbat_private
    Subject: Subst.exe carelessness
    
    
    	In our environment, we use both the subst and net use commands to setup
    the users' environment during logon. In order to avoid any errors, our
    logon scripts simply include subst *drive_letter* /d statements for all
    drive letters that we use. This ensures that the machine has no previous
    mappings before the rest of the script is run.
    
    
    	if exist g: subst g: /d
    	if exist h: subst h: /d
    	if exist t: subst t: /d
    	if exist z: subst z: /d
    	
    	subst g: c:\data
    	subst h: c:\apps
    	net use t: \\server\server_apps
    	net use z: \\server\user_home
    
    
    	We find that this solution is simple for our environment. And as the
    exploit that you point out will only work to spoof drive mappings that
    *should* exist in a normal user environment, this simple script addition
    will eliminate that problem.
    
    
    	David Anders
    	dmandersat_private
    



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