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I'm watching at forums.gentoo.org, and see that you are using phpBB 2.0.0, and a few days ago in bugtraq there was an advisory about this forum. |
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|
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Advisory: |
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|
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From: Martijn Boerwinkel <xim@××××××.nl> |
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To: bugtraq@×××××××××××××.com |
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Subject: Cross Site Scripting Vulnerability in phpBB2's [IMG] tag and remote avatar |
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Date: 26 May 2002 17:59:33 +0200 |
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X-Mailer: Ximian Evolution 1.0.5 |
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|
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phpBB2 Cross Site Scripting Vulnerability |
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-------------------------------------------- |
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|
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Affected Program: phpBB2 version 2.0.0 |
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(possibly earlier versions too, but not tested) |
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Vendor: http://www.phpbb.com |
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Vendor Status: informed on 24/04/2002, fixed issued on 20/05/2002 |
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Discovery Date: 24/04/2002 |
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Release Date: 26/05/2002 |
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Vulnerability Class: Cross Site Scripting |
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|
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|
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Severity |
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-------- |
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Malicious users can steal other user's and admin's cookies, allowing |
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them to impersonate other users on the board and access to the |
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administration panel. |
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|
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Problem |
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------- |
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The problem is very similar to SQL injection. |
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phpBB2 uses a user provided string (through the [IMG] tag) |
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in the following HTML tag: |
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|
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<img src="$user_provided" border="0" /> |
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|
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While there is a check to force the string to begin with "http://" it |
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doesn't disallow ". That means a malicious user can escape the src="" in |
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the HTML tag and insert his own html code. |
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This same problem also exists in the remote avatar part of the user |
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profile. |
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|
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|
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Example |
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------- |
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Enter the following anywhere in a message: |
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|
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[img]http://a.a/a"onerror="javascript:alert(document.cookie)[/img] |
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|
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When reading that message it should popup an alert box with your |
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cookies. |
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|
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Solutions |
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--------- |
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* Upgrade to 2.0.1 |
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|
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-- |
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XiM |
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(#icerealm on irc.icerealm.net) |
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|
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----------------------------- |
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Well, if you didn't know, now you know...hehe, sorry about my english :-) |
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best regards. |
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|
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-- |
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When tux flies, Chuck will die... |
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|
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TripleDES <TripleDES@××××××.org> - http://bsdsite.no-ip.org |
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