Horde 3.3.5 Cross Site Scripting

`=============================================  
INTERNET SECURITY AUDITORS ALERT 2009-012  
- Original release date: October 13th, 2009  
- Last revised: December 16th, 2009  
- Discovered by: Juan Galiana Lara  
- CVE ID: CVE-2009-3701  
- Severity: 6.3/10 (CVSS Base Score)  
=============================================  
  
I. VULNERABILITY  
-------------------------  
Horde 3.3.5 "PHP_SELF" Cross-Site Scripting vulnerability  
  
II. BACKGROUND  
-------------------------  
The Horde Application Framework is a modular, general-purpose web  
application framework written in PHP. It provides an extensive array  
of classes that are targeted at the common problems and tasks involved  
in developing modern web applications.  
  
III. DESCRIPTION  
-------------------------  
Input passed to 'PHP_SELF' variable is not properly filtered before  
being returned to the user. This can be explotied to inject arbitrary  
HTML or to execute arbitrary script code in a user's browser session  
in context of an affected site. In order to successfully exploit this  
vulnerability the targeted user has to be logged as an administrator.  
  
horde-3.3.5/admin/cmdshell.php:46:<form action="<?php echo  
$_SERVER['PHP_SELF'] ?>" method="post">  
horde-3.3.5/admin/sqlshell.php:29:<form name="sqlshell" action="<?php  
echo $_SERVER['PHP_SELF'] ?>" method="post">  
horde-3.3.5/admin/phpshell.php:42:<form action="<?php echo  
$_SERVER['PHP_SELF'] ?>" method="post">  
  
In order to filter the "PHP_SELF" variable, the htmlspecialchars  
function has to be used, like in  
'horde-3.3.5/templates/shares/edit.inc' file:  
  
horde-3.3.5/templates/shares/edit.inc:1:<form name="edit"  
method="post" action="<?php echo  
htmlspecialchars($_SERVER['PHP_SELF']) ?>">  
  
IV. PROOF OF CONCEPT  
-------------------------  
This PoC will show an alert with the text "xss"  
  
http://site/horde-3.3.5/admin/phpshell.php/%22%3E%3Cscript%3Ealert%288%29;%3C/script%3E%3Cform%20/?Horde=<sessid>  
http://site/horde-3.3.5/admin/cmdshell.php/%22%3E%3Cscript%3Ealert%288%29;%3C/script%3E%3Cform%20/?Horde=<sessid>  
http://site/horde-3.3.5/admin/sqlshell.php/%22%3E%3Cscript%3Ealert%288%29;%3C/script%3E%3Cform%20/?Horde=<sessid>  
  
V. BUSINESS IMPACT  
-------------------------  
Is possible to execute arbitrary HTML or script code in a targeted  
user's browser. Only works with administration sessions.  
  
VI. SYSTEMS AFFECTED  
-------------------------  
Horde 3.3.5 is vulnerable, others may be affected.  
  
VII. SOLUTION  
-------------------------  
Upgrade to version 3.3.6  
  
VIII. REFERENCES  
-------------------------  
http://www.horde.org  
http://lists.horde.org/archives/announce/2009/000529.html  
http://www.isecauditors.com  
  
IX. CREDITS  
-------------------------  
This vulnerability has been discovered by  
Juan Galiana Lara (jgaliana (at) isecauditors (dot) com).  
  
X. REVISION HISTORY  
-------------------------  
October 13, 2009: Initial release  
October 19, 2009: Added CVE id.  
December 13, 2009: Revision.  
December 16, 2009: Las revision.  
  
XI. DISCLOSURE TIMELINE  
-------------------------  
October 13, 2009: Vulnerability discovered by  
Internet Security Auditors.  
October 13, 2009: Sent to developers.  
The issue is considered hard to exploit and  
solution is delayed.  
December 13, 2009: Second contact for correction plan.  
December 15, 2009: New release published.  
December 16, 2009: Sent to public lists.  
  
XII. LEGAL NOTICES  
-------------------------  
The information contained within this advisory is supplied "as-is"  
with no warranties or guarantees of fitness of use or otherwise.  
Internet Security Auditors accepts no responsibility for any damage  
caused by the use or misuse of this information.  
`