LS Simple Guestbook 1.0 - Remote Code Execution

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#   Special Greetings To - Timq,Warpboy,The-Maggot     #
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File: index.php
Affects: LS simple guestbook (v1)
Date: 15th April 2007

Issue Description:
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LS simple guestbook fails to sanitize user input that it writes to the
posts.txt file when the user leaves a message, this file is then included
causing any php code within it to be run.
===========================================================================

Scope:
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An attacker can inject arbitrary php code and potentially execute commands
on the system.
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Recommendation:
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Add the following line of code in index.php:

$message = strip_tags($message);

just above:

if ($message != "") {$file = fopen("$dataf","a");
===========================================================================


Example:

name = Test
message = <?php phpinfo(); ?>


Discovered By: Gammarays

# milw0rm.com [2007-04-14]