Re: war-ftpd 1.6x DoS

From: Jarle Aase (jgaaat_private)
Date: Wed Feb 02 2000 - 23:41:34 PST

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    I can confirm that version 1.6* have a problem, as described in the initial report.
    
    Until now, the command parser in War FTP Daemon 1.6* has allowed commands up to 8 KB in size. To prevent this, and other buffer-overflow problems, this size is decreased to (MAX_PATH + 8), and an additional check is added that prevents any command argument to exceed MAX_PATH in length. 
    
    A new version, 1.67-4 has been released with this modification. See http://war.jgaa.com/alert/ for download details.
    
    Jarle Aase
    
    
    > -----Original Message-----
    > From: Bugtraq List [mailto:BUGTRAQat_private]On Behalf Of
    > Toshimi Makino
    > Sent: Tuesday, February 01, 2000 8:59 AM
    > To: BUGTRAQat_private
    > Subject: war-ftpd 1.6x DoS
    > 
    > 
    > Hello,
    > 
    > 
    > "war-ftpd" is very popular ftp server for Windows95/98/NT.
    > I found DoS problem to "war-ftpd 1.6x" recently.
    > 
    > 
    > Outline:
    >   It seems to occur because the bound check of the command of MKD/CWD
    >   that uses it is imperfect when this problem controls the directory.
    > 
    >   However, could not hijack the control of EIP so as long as I test.
    >   It is because not able to overwrite the RET address,
    >   because it seems to be checking buffer total capacity properly
    >   in 1.66x4 and later.
    > 
    >   The boundary of Access Violation breaks out among 8182 bytes
    >   from 533 bytes neighborhood although it differs by the thread
    >   that receives attack.
    > 
    > 
    > The version that is confirming this vulnerable point is as follows.
    >   1.66x4s, 1.67-3
    > 
    > 
    > The version that this vulnerable point was not found is as follows.
    >   1.71-0
    [...]
    



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