An inofficial fix to this Issue has been released by ghcif.de PHPBB 2.0.6c XSS Flaw in viewtopic.php
Open and Backup viewtopic.php
Find:
if ( !empty($HTTP_POST_VARS['postorder']) || !empty($HTTP_GET_VARS['postorder']${
$post_order = (!empty($HTTP_POST_VARS['postorder'])) ? $HTTP_POST_VARS[$
$post_time_order = ($post_order == "asc") ? "ASC" : "DESC";
}
else
{
$post_order = 'asc';
$post_time_order = 'ASC';
}
Replace with:
//
// Decide how to order the post display
//
if ( !empty($HTTP_POST_VARS['postorder']) || !empty($HTTP_GET_VARS['postorder']${
$post_order = (!empty($HTTP_POST_VARS['postorder'])) ? $HTTP_POST_VARS[$
// Exploit Fix
$post_order = htmlspecialchars($post_order);
$post_time_order = ($post_order == "asc") ? "ASC" : "DESC";
}
else
{
$post_order = 'asc';
// Exploit Fix
$post_order = htmlspecialchars($post_order);
$post_time_order = 'ASC';
}
by Milan 't4c' Berger
Cheng Peng Su wrote:
################################################
Advisory Name:New phpBB ViewTopic.php Cross Site Scripting Vulnerability
Release Date: Feb 29,2004 Application: phpBB Platform: PHP
Version Affected: the lastest version
Vendor URL: http://www.phpbb.com/
Discover: Cheng Peng Su(apple_soup_at_msn.com)
################################################
Details: This vuln is similar to Arab VieruZ's advisory 'XSS bug in phpBB',this time the problem is not in 'highlight' ,but in 'postorder'.we can inject HTML code,such code could be used to steal cookie information.
Proof of Concept:
If there is a topic at http://site/phpBB/viewtopic.php?t=123456
this page can be also viewed at
http://site/phpBB/viewtopic.php?t=123456&postorder=asc
then this page will contain code like below:
<a class="maintitle" href="viewtopic.php?t=176994&start=0&postdays=0&postorder=asc&highlight=">[Topic Title]</a>.
phpBB doesn't filter out illegal characters from 'postorder',so we can inject HTML code after 'postorder='.
Exploit: URL: http://site/phpBB/viewtopic.php?t=123456&postorder=%22%3E%3C%73%63%72%69%70%74%3E%61%6C%65%72%74%28%64%6F%63%75%6D%65%6E%74%2E%63%6F%6F%6B%69%65%29%3C%2F%73%63%72%69%70%74%3E%3C
note unescape('=%22%3E%3C%73%63%72%69%70%74%3E%61%6C%65%72%74%28%64%6F%63%75%6D%65%6E%74%2E%63%6F%6F%6B%69%65%29%3C%2F%73%63%72%69%70%74%3E%3C') == '"><script>alert(document.cookie)</script><'
Contact: Cheng Peng Su apple_soup_at_msn.com Class 1,Senior 2,High school attached to Wuhan University Wuhan,Hubei,China
-- Milan 't4c' Berger Network & Security Administrator 21073 Hamburg
gpg: http://www.ghcif.de/keys/t4c.asc
