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Re: CVE affected for PHP 5.3.9 ?
From: Kurt Seifried <kseifried () redhat com>
Date: Sat, 14 Jan 2012 12:31:12 -0700

On 01/14/2012 12:03 PM, Ignacio Espinosa wrote:
On Fri, 13 Jan 2012 13:50:59 -0700
Kurt Seifried <kseifried () redhat com> wrote:
[...]
Ok I'm still not clear on what the security claim is. Are you saying you
can cause arbitrary text output via XSL/XML mangling tricks? And
combined with having a script that uses something like "<sax:output
href="0wn3d.php" method="text">" you can put arbitrary text content into
this file which could then result in the file being parsed? The problem
is you'd have to write a script that does this, writes to a local file
with a file ending in .php or .shtml or whatever, in which case it's
pretty clear the script writer MEANT to do that. Again I'm still not
clear on what/how a security boundary is being crossed. How does this
elevate privileges or give you remote access that you wouldn't already
if you can upload arbitrary PHP scripts?


You don't need to upload arbitrary php scripts to make this works. Just uploading a crafted xslt file will create 
(before patch)  a file with arbitrary content, php code for example, as write-access is set for default.

-- snip --
        <sax:output href="0wn3d.php" method="text">
        <xsl:value-of select="'&lt;?php system(\$_GET[&quot;cmd&quot;]);?&gt;'"/>
-- snip --



Right but the script has to have the line

<sax:output href="0wn3d.php" method="text">

which means the author really meant to do this (output a php or shtml or whatever file), or can the attacker somehow 
control the output href commonly? It appears that this is not the case. This does not appear to be a security 
vulnerability. 

-- 

-- Kurt Seifried / Red Hat Security Response Team


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