Re: Forwared to me

From: Illuminatus Primus (vermontat_private)
Date: Mon Jul 13 1998 - 09:54:11 PDT

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    On Fri, 10 Jul 1998, Solar Designer wrote:
    
    > > # mv /usr/bin/finger /usr/bin/finger.exe
    > > # cat > /usr/bin/finger
    > > #!/bin/sh
    > > exec /usr/bin/finger.exe -m $*
    > > ^D
    > > # chmod +x /usr/bin/finger
    >
    > Hmm, weird, this doesn't look safe to me. Why trust the extra parsing done
    > by the shell?
    >
    
    Which happens to include filename globbing.
    
    This "fix" will now allow people to do:
    
    finger '/*@hostname'..
    
    Which could reveal a lot more information than finger was intended to..
    
    Not to mention
    
    finger '/*/*/*/*/*@hostname'
    
    .. which might turn out to be a far worse DOS than the original attack.
    
    If we are forced to use a shell,
    #!/bin/sh
    exec /usr/bin/finger -m "$*"
    
    will prevent the arguments from being globbed, at least with my version of
    bash (2.02.0(1)-release).
    
    -Illuminatus Pimpus
     vermontat_private
    



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