Re: con\con is a old thing (anyway is cool)

From: Stephen White (swhiteat_private)
Date: Wed Mar 08 2000 - 07:01:53 PST

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    On Mon, Mar, 2000, Ussr Labs wrote:
    > for: windoze 98 maybe 95 too...
    > not for NT4 or win2K
    >
    > When we looked at the new exploit for ie that uses the image
    > c:/con/con
    > (http://www.zoomnet.net/~quick/error/crash.html)
    >
    > This can also be exploited to crash remote servers
    > Look what we tryed on this servU-FTP v 2.4a
    > (works on any windoze 98 FTP even with anonyous or guest account)
    
    Just to reinforce what is being said this is the fault of a some API
    call in Windows 95 and 98 (Not NT), and so affects many different
    programs.  The severity seems to vary from a recoverable BSOD to a
    complete lockup.
    
    This can be exploited by simply attempting to open a file or directory
    called "con\con" (or "nul\nul") and there are many ways to achieve this:
    
    Locally just type "dir con\con" into a MS-DOS Prompt Window, or opening
    a webpage with the <IMG SRC="c:\con\con"> tag in I.E. (presumably other
    browsers too).
    
    Remotely:
    
    Gene6 - G6 FTP Server v2.0 - login and type 'ls con/con' .. I'm sure
    most Windows FTPds and possibly HTTPds can be exploited in the same way
    (Sambar HTTP Server 4.3 seems safe though).
    
    If the machine has a directory shared with the standard SMB File &
    Printer Sharing (even read only shares) it can also be hit:
    
    [stephen@eddie stephen]$ smbclient //eddie95/TEST -I 172.16.61.2
    Added interface ip=172.16.61.1 bcast=172.16.61.255 nmask=255.255.255.0
    Password:
    smb: \> ls con\con
    
    Sure enough Eddie95 BSODs.  It is running Windows 95 OSR 2.
    
    --
    Stephen White <swhiteat_private>
    



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