Re: Buffer overflow in Explorer.exe

From: Ryan Yagatich (ryanyat_private)
Date: Thu May 08 2003 - 15:28:21 PDT

  • Next message: Kristopher Matthews: "RE: Buffer overflow in Explorer.exe"

    Hi, 
    	I don't quite understand the purpose behind this code. It creates
    a read only file '/aT4r[at]3WDesign.es Security/desktop.ini' with the
    contents of
    
    [.ShellClassInfo]
    AAAAAAAAAAAA {x2301}
    
    
    	And then terminates? I don't have a windows machine available to
    really explore this any, but what makes that entry in desktop.ini cause
    this? Furthermore, is this issue only for that particular key or is it
    generally just key/excessive parameter/missing value size that is
    affected? And additionally, you mention that explorer will no longer be
    able to operate when trying to browse the hard disk, but does this mean
    globally, or when they try to browse the c:/ drive, or just that
    particular folder?
    	Please send me more information about this, (even if it references
    past posts that I have missed) so that I can better understand the
    severity of this. Espcially since to me, I still see it as someone needing
    to download and execute untrusted software which causes a system crash, 
    and if that were going to happen there are far worse things that can be 
    done besides creating a small text file.
    
    Thanks,
    Ryan Yagatich
    
    
    ,_____________________________________________________,
    \ Ryan Yagatich                     supportat_private \
    / Pantek Incorporated                  (877) LINUX-FIX /
    \ http://www.pantek.com/security        (440) 519-1802 \
    /       Are your networks secure? Are you certain?     /
    \___E8354282324E636DB5FF7B8A6EDED51FD02C06C68D3DB695___\
    
    On Wed, 7 May 2003, aT4r InsaN3 wrote:
    
    >This bug allow a malicious an attacker to execute data with privileges of a 
    >user that is browsing the hard disk with explorer.
    >
    >tested against winxp SP1
    >
    >example code provided.
    >
    <snip>
    >
    >	strcpy(path,"\\aT4r[at]3WDesign.es Security");
    >	mkdir(path);
    >	SetFileAttributes(path,FILE_ATTRIBUTE_READONLY);
    >
    >	strcat(path,"\\desktop.ini");
    
    >	bof=fopen(path,"w");
    >	fputs("[.ShellClassInfo]\n",bof);
    >	memset(evil,'A',BUFF);
    >	fputs(evil,bof);
    >	fclose(bof);
    <snip>
    



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