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Old February 21st, 2007, 09:33 AM
dparsons dparsons is offline
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That statement is an example.

What he is saying is that, if a user comes to your site with the intent on executing malicious scripts and all you are doing to is checking the file exetension of the file with JavaScript to ensure it is ok to upload, this user could disable javascript in their browser and now could upload an ASP file to your upload directory.

If that code contained this script:

<%
  dim fs
  Set fs=Server.CreateObject("Scripting.FileSystemObject ")
  fs.DeleteFile("c:\SomeImportantFile.txt")
%>

It would potentially delete a file off of your C drive because all the user would have to do is navigate to the directory you upload files to, and execte the ASP file that he just uploaded and you are none the wiser that an asp script was uploaded. (Until you go looking for the important file that just got deleted off of your c drive.)

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Read this if you want to know how to get a correct reply for your question:
http://www.catb.org/~esr/faqs/smart-questions.html
^^Took that from planoie's profile^^
^^Modified text taken from gbianchi profile^^
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Technical Editor for: Professional Search Engine Optimization with ASP.NET
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Discussion:
http://p2p.wrox.com/topic.asp?TOPIC_ID=56429
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