Re: FW: Buffer overflow in Serve-U (fwd)

From: Chuck Rock (carockat_private)
Date: Sat Feb 13 1999 - 08:50:40 PST

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    This message is forwarded from one of the programmers for Serv-U FTP
    software....
    
    ---------- Forwarded message ----------
    Date: Fri, 12 Feb 1999 21:04:55 -0500
    From: Rob Beckers <Rob@cat-soft.com>
    Reply-To: serv-u@cat-soft.com
    To: serv-u@cat-soft.com
    Subject: Re: FW: Buffer overflow in Serve-U
    
    As far as I know Serv-U v2.4a won't crash on NT4. It will crash on Win95/98
    if someone sends large blocks of junk. I've traced those crashes to happen
    in KERNEL32.EXE, and the call stack does not show any Serv-U involvement
    (except that the DLL was working on Serv-U's behalf so it crashes the
    Serv-U task). This seems to be a bug in MS's socket stack and not something
    I can fix.
    
    If someone has code that crashes Serv-U 2.4a on NT4 please let me know. I'd
    be very interested in tracing the crash in Serv-U in that case, and fix
    things if possible.
    
            Rob
            -/-
    
    -- "An eye for an eye will leave the whole world blind" (Gandhi) --
        Check out http://www.ftpserv-u.com for all about Serv-U v2.4a
    -------------------------------------------------------------------
    
    
    --On Friday, February 12, 1999, 2:34 PM -0500 Chuck Rock
    <carockat_private> wrote:
    
    > Is this for real?
    >
    > -----Original Message-----
    > From: Bugtraq List [mailto:BUGTRAQat_private] On Behalf Of Ryan Sweat
    > Sent: Thursday, February 11, 1999 9:36 PM
    > To: BUGTRAQat_private
    > Subject: Buffer overflow in Serve-U
    >
    >
    >      I have successfully reprocuded this overflow in the newest Version of
    > Serve-U.
    > It totally crashes the ftp program, and also causes stack fault module in
    > tcp/ip stack rendering the network connectivity useless.  About 10 seconds
    > later, the machine will become unresponsive and has to be hard rebooted.
    > This affects every Win98 machine i have tested on, however, an NT box with
    > SP4 hung the program until the exploit was killed, but not crashing the
    > serve-u itself.
    >      The exploit is very simple.
    > Send a file about 1 meg in size to serve-u's ftp port (21).  This can be
    > done with
    >      cat filename | nc hostname 21
    >
    > Ryan Sweat
    > ryansat_private
    >
    
    
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