eFront-learning PHP file inclusion vulnerability

Core Security - CoreLabs


eFront-learning PHP file inclusion vulnerability

1.
Advisory Information

Title: eFront-learning PHP file inclusion vulnerability
Advisory Id: CORE-2010-0311
Advisory URL: http://www.coresecurity.com/content/efront-php-file-inclusion

Date published: 2010-03-16
Date of last update: 2010-03-16
Vendors contacted: Vendor name
Release mode: Coordinated release

2.
Vulnerability Information

Class: PHP file inclusion [CWE-98]

Impact: Code execution
Remotely Exploitable: Yes
Locally Exploitable: No
Bugtraq ID: N/A
CVE Name: N/A

3.
Vulnerability Description

eFront [1] is an easy-to-use, open source and object-oriented multilingual eLearning platform that can be used to build learning communities, educate and retain the end-users.

eFront is vulnerable to local file inclusion vulnerability, which allows an external remote attacker to upload an arbitrary file and execute code on the vulnerable website learning platform.

4.
Vulnerable packages

  • eFront v3.5.5.
  • Older versions are probably affected too, but they were not checked.

5.
Non-vulnerable packages

  • eFront v3.6.


6.
Vendor Information, Solutions and Workarounds

We have issued a patch that addresses this problem, as well as a new eFront 3.5.5 bundle that includes the fix.

  • Link to the patch: here.
  • Link to the corresponding forum announcement and discussion: here.
  • Link to the corresponding web site announcement: here.

7.
Credits

This vulnerability was discovered and researched by 7safe's Penetration Testing Team, [2].

8.
Technical Description / Proof of Concept Code

eFront-learning is vulnerable to local file inclusion vulnerability. The file language.php located in /www/editor/tiny_mce/langs/language.php has the following code:

include_once $path."language/lang-".$_GET['langname'].".php.inc";

Thus any arbitrary file can be included, using the following attack vector:

http://192.168.xxx.xxx/efront/www/editor/tiny_mce/langs/language.php?lan...

Magic quote must be disabled for successful inclusions of files with extensions other than .php.inc.

Further, the software allows files with extension .php.inc to be uploaded on to the server. These files can be uploaded as a user in student role via send-message functionality (attaching a file with extension .php.inc).

http://192.168.xxx.xxx/efront/www/forum/new_message.php

The attached document gets saved in directory:

/wwwroot/www/efront/upload/[username]/message_attachments/Sent/[timestamp]/

The value of the directory name [timestamp] can be calculated by passing the date/time of the message sent (can be found in Tools->Messages->Sent functionality) as the input parameters to the PHP function mktime(). For example, echo mktime(18, 15, 29, 2, 22, 2010) gives us 1266862529.

Once the file location of the uploaded file has been obtained, then remote code can be executed on the vulnerable website by including this malicious file:

http://localhost:81/efront/www/editor/tiny_mce/langs/language.php?langna...

If the malicious file malicious.php.ini would contain following code:

<?php
   passthru("net users");
?>

Attacker will be able to enumerate users on target machine.

9.
Report Timeline

  • 2010-03-11:
    Core Security Technologies notifies the eFront team of the vulnerability.
  • 2010-03-12:
    The eFront team asks Core for a technical description of the vulnerability.
  • 2010-03-12:
    Technical details sent to eFront team by Core. Core notifies that the flaw was probably fixed in eFront v3.6 (publicly available).
  • 2010-03-12:
    eFront team confirms the flaw was fixed in v3.6 and they will issue a patch for versions 3.5.5 and below. eFront team also notifies the patches for old version will be available next Monday, 2010-Mar-15.
  • 2010-03-12:
    Core announces its plan to publish the advisory on March 16th, 2010.
  • 2010-03-12:
    The eFront team notifies that are in agreement with the proposed disclosure date.
  • 2010-03-15:
    The eFront team notifies that they have issued a patch that addresses the problem, as well as a new efront 3.5.5 bundle that includes the fix (See section 6).
  • 2010-03-16:
    The advisory CORE-2010-0311 is published.

10.
References

[1] http://www.efrontlearning.net/.
[2] http://www.7safe.com/.

11.
About CoreLabs

CoreLabs, the research center of Core Security Technologies, is charged with anticipating the future needs and requirements for information security technologies. We conduct our research in several important areas of computer security including system vulnerabilities, cyber attack planning and simulation, source code auditing, and cryptography. Our results include problem formalization, identification of vulnerabilities, novel solutions and prototypes for new technologies. CoreLabs regularly publishes security advisories, technical papers, project information and shared software tools for public use at: http://www.coresecurity.com/corelabs.

12.
About Core Security Technologies

Core Security Technologies develops strategic solutions that help security-conscious organizations worldwide develop and maintain a proactive process for securing their networks. The company's flagship product, CORE IMPACT, is the most comprehensive product for performing enterprise security assurance testing. CORE IMPACT evaluates network, endpoint and end-user vulnerabilities and identifies what resources are exposed. It enables organizations to determine if current security investments are detecting and preventing attacks. Core Security Technologies augments its leading technology solution with world-class security consulting services, including penetration testing and software security auditing. Based in Boston, MA and Buenos Aires, Argentina, Core Security Technologies can be reached at 617-399-6980 or on the Web at http://www.coresecurity.com.

13.
Disclaimer

The contents of this advisory are copyright (c) 2010 Core Security Technologies and (c) 2010 CoreLabs, and may be distributed freely provided that no fee is charged for this distribution and proper credit is given.

14.
PGP/GPG Keys

This advisory has been signed with the GPG key of Core Security Technologies advisories team, which is available for download at /legacy/files/attachments/core_security_advisories.asc.

Locally Exploitable: 
no
Remotely Exploitable: 
no
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