.:. MicroGuestBook Remote XSS Bug .:.

Date:

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July 2006, 22

Product:

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MicroGuestBook Latest Version

Vendor:

-------

http://www.phptoys.com

Description:

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Micro guestbook is a MySQL based guestbook script with a CSS based attractive interface. It can store the name, date,

message, location, web and email information of the visitor.

Exploit(s)/Advisory(ies):

-------------------------

The application is vulnerable to a Remote XSS Bug. The field 'name' and 'comment' are not properly sanitized before being

used, so a malicious people can exploit this vulnerability to inject arbitrary HTML and script code.

If you look the code in add.php you can see:

[...]

if (isset($_POST['submitBtn'])) {

$name     = (isset($_POST['name'])) ? $_POST['name'] : '' ;

$comment  = (isset($_POST['comment'])) ? $_POST['comment'] : '' ;

$location = (isset($_POST['location'])) ? $_POST['location'] : '' ;

$website  = (isset($_POST['website'])) ? $_POST['website'] : '' ;

$email    = (isset($_POST['email'])) ? $_POST['email'] : '' ;

$actDate  = date("Y-m-d H:i:s");

//Minimum name and comment length.

if ((strlen($name) > 2) && (strlen($comment) > 5)){

$sql = "INSERT INTO guestbook (name,text,insertdate,location,web,email) VALUES (";

$sql .= "'".$name."','".$comment."','".$actDate."','".$location."','".$website."
','".$email."')";

$MyDb->f_ExecuteSql($sql);

[...]

And in index.php you will see:

[...]

<div id="name"><?php echo $row['name']; ?></div>

<div id="info">

<div id="infoicons">

<?php

if (strlen($row['web']) > 5) echo '<a href="http://'.$row['web'].'"><img src="style/www.gif"></a>';

if (strlen($row['email']) > 5) echo '<a href="mailto:'.$row['email'].'"><img src="style/mail.gif"></a>';

?>

</div>

<div id="infodate"><?php echo $row['insertdate']; ?></div>

</div>

</div>

<div id="base">

<div id="icon"><?php echo $row['location']; ?></div>

<div id="text"><?php echo nl2br($row['text']); ?></div>

[...]

PoC(s):

-------

You can put your own HTML or script code in the field name or comment. Try:

<script>alert("XSS")</script>

Vendor Status:

--------------

[July 2006, 22] Vendor contacted!

Patches:

--------

[July 2006, 22] At the moment there is no patch available from the vendor. You can take a look at this site if a patch will

be posted up:

http://www.phptoys.com

If you don't wanna wait, edit the source code to ensure  that input is properly sanitised.

Credits:

--------

omnipresent

omnipresent[at]email[dot]it

http://it.security.netsons.org