Advisory: Information Disclosure in TYPO3 Extension ke_questionnaire

The TYPO3 extension ke_questionnaire stores answered questionnaires in a
publicly reachable directory on the webserver with filenames that are
easily guessable.


Details
=======

Product: ke_questionnaire 
Affected Versions: 2.5.2 (possibly all versions)
Fixed Versions: unknown
Vulnerability Type: Information Disclosure
Security Risk: medium
Vendor URL: http://kequestionnaire.kennziffer.com/
Vendor Status: notified
Advisory URL: https://www.redteam-pentesting.de/advisories/rt-sa-2014-009
Advisory Status: published
CVE: CVE-2014-8874
CVE URL: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-8874


Introduction
============

"The TYPO3 extension kequestionnaire allows to easily and quickly create
and evaluate individual questionnaires online in any TYPO3 website."

(translated from the official website of ke_questionnaire)


More Details
============

Files containing the answered questionnaires are stored in the
"typo3temp" directory within the TYPO3 installation. As the source code
of the ke_questionnaire extension shows, the filename of an answered
questionnaire is solely based on the questionnaire ID and the user ID of
the user who created the questionnaire.

Source code (shortened):
------------------------------------------------------------------------------
function init() {
    global $BE_USER,$LANG,$BACK_PATH,$TCA_DESCR,$TCA,$CLIENT,$TYPO3_CONF_VARS;

    $this->temp_file = \
'tx_kequestionnaire_temp_'.$this->q_id.'_'.$GLOBALS['BE_USER']->user['uid'];
    [...]
}
[...]
function createSchedulerTask(){
    $myVars = $GLOBALS['BE_USER']->getSessionData('tx_kequestionnaire');
    $file_path = PATH_site.'typo3temp/'.$this->temp_file;
    [...]
}
------------------------------------------------------------------------------

A valid URL that returns the answers to a questionnaire could look like
the following:

http://www.example.com/typo3temp/tx_kequestionnaire_temp_15999_7



Proof of Concept
================

Using the tool wfuzz[1] it is possible to search for answers to
questionnaires on a TYPO3 site that employs ke_questionnaire:

------------------------------------------------------------------------
$ python wfuzz.py -c -z range,14000-15000 -z range,1-10 --hc 301 \
  http://example.com/typo3temp/tx_kequestionnaire_temp_FUZZ_FUZ2Z
------------------------------------------------------------------------


Workaround
==========

The webserver config should deny access to answered questionnaire files,
for example by adding an .htaccess file that limits access to
tx_kequestionnaire_* files (this may hinder online evaluation of the
questionnaires).


Fix
===

No official fix available.


Security Risk
=============

Depending on the questions in the questionnaire the answered
questionnaires may contain personal information including participants'
full names, addresses and so on. The risk therefore strongly depends on
the information supplied in the questionnaires. Since this information
will at least often contain email addresses, it is rated as at least a
medium risk.


Timeline
========

2014-04-21 Vulnerability identified
2014-04-30 Customer approved disclosure to vendor
2014-05-13 Vendor notified
2014-05-20 Vendor works with TYPO3 security team on a fix
2014-06-15 Vendor releases updated version which according to them
           does not fix the issue
2014-10-08 TYPO3 security team says the issue is still unresolved
2014-11-04 Vendor continues to release updated versions, no response
           whether the security issue is fixed
2014-11-14 CVE number assigned
2014-12-01 Advisory released


References
==========

[1] https://code.google.com/p/wfuzz/


RedTeam Pentesting GmbH
=======================

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