Onderwerp: Cross-Site Scripting (XSS) in Php-Nuke 7.1.0

Affected software description:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Php-Nuke is popular freeware content management system, written in php by
Francisco Burzi. This CMS (COntent Management System) is used on many thousands
websites, because it`s free of charge, easy to install and has broad set of features.

Homepage: http://phpnuke.org


Vulnerabilities:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If we look at Php-Nuke`s history, then we can find many cases reporting the XSS
in Php-Nuke. Most of them are fixed by now, when we have allready version 7.1.0
available. Despite this I found two new cases of XSS in Php-Nuke 6.x-7.1.0 , maybe in
older versions too.


Exploit:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Let`s look at code from "/modules/News/friend.php" line 84-92 (Php-Nuke 7.1.0):


function StorySent($title, $fname) {
include ("header.php");
$title = urldecode($title);
$fname = urldecode($fname);
OpenTable();
echo "<center><font class=\"content\">"._FSTORY." <b>$title</b> "._HASSENT." $fname... "._THANKS."</font></center>";
CloseTable();
include ("footer.php");
}


If we deliver $title or $fname by GET or POST variable, then we have XSS
conditions here. But Php-Nuke will reject GET and POST requests with &lt;script&gt; tags.
One way to evade this filter is the using of <img src=foo onload=[code here]>.

There is better way to exploit the XSS, and it`s the using of partially or fully
urlencoded ("hexed") script for exploit. And because we have lines

$title = urldecode($title);

and

$fname = urldecode($fname);

in original code, it will be urldecoded and will work for us, but GET or POST
filtering can`t recognize the "&lt;script&gt;" pattern.

Same problem has one more module - "Reviews".


Proof of concept examples:

http://f00bar.com/modules.php?name=N...le=%253cscript>alert%2528document.cookie);%253c/script>

http://f00bar.com/modules.php?name=R...le=%253cscript>alert%2528document.cookie);%253c/script>



==================
Abu Lafy

Uhm.. Why does your proof match almost exactly what was posted back on
10 February?

http://www.net-security.org/vuln.php?id=3245

I mean.. even down to the examples. Come on!

-Anthony


On 17 Aug 2004 12:28:36 -0000, Abu Lafy <off@hotmail.com> wrote:
>
>
> Affected software description:
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Php-Nuke is popular freeware content management system, written in php by
>
> Francisco Burzi. This CMS (COntent Management System) is used on many thousands
>
> websites, because it`s free of charge, easy to install and has broad set of features.
>
> Homepage: http://phpnuke.org
>
> Vulnerabilities:
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> If we look at Php-Nuke`s history, then we can find many cases reporting the XSS
>
> in Php-Nuke. Most of them are fixed by now, when we have allready version 7.1.0
>
> available. Despite this I found two new cases of XSS in Php-Nuke 6.x-7.1.0 , maybe in
>
> older versions too.
>
> Exploit:
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Let`s look at code from "/modules/News/friend.php" line 84-92 (Php-Nuke 7.1.0):
>
> function StorySent($title, $fname) {
>
> include ("header.php");
>
> $title = urldecode($title);
>
> $fname = urldecode($fname);
>
> OpenTable();
>
> echo "<center><font class=\"content\">"._FSTORY." <b>$title</b> "._HASSENT." $fname... "._THANKS."</font></center>";
>
> CloseTable();
>
> include ("footer.php");
>
> }
>
> If we deliver $title or $fname by GET or POST variable, then we have XSS
>
> conditions here. But Php-Nuke will reject GET and POST requests with &lt;script&gt; tags.
>
> One way to evade this filter is the using of <img src=foo onload=[code here]>.
>
> There is better way to exploit the XSS, and it`s the using of partially or fully
>
> urlencoded ("hexed") script for exploit. And because we have lines
>
> $title = urldecode($title);
>
> and
>
> $fname = urldecode($fname);
>
> in original code, it will be urldecoded and will work for us, but GET or POST
>
> filtering can`t recognize the "&lt;script&gt;" pattern.
>
> Same problem has one more module - "Reviews".
>
> Proof of concept examples:
>
> http://f00bar.com/modules.php?name=N...le=%253cscript>alert%2528document.cookie);%253c/script>
>
> http://f00bar.com/modules.php?name=R...le=%253cscript>alert%2528document.cookie);%253c/script>
>
> ==================
>
> Abu Lafy
>
>


--
Anthony Petito