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# Exploit Title: Adobe.com Flashplayer sub-domain Reflected XSS (RXSS)
# Date: 08/12/2014
# Author: Yann CAM @ Synetis - ASafety
# Vendor or Software Link: www.adobe.com
# Version: /
# Category: Reflected Cross Site Scripting
# Google dork:
# Tested on: Adobe.com Flashplayer sub-domain
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Adobe description :
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Adobe Systems Incorporated is a multinational computer software company. Adobe Systems headquarter is based in San Jose, California, United States. 
The company has historically focused upon the creation of multimedia and creativity software products, with a more-recent foray towards rich Internet 
application software development. It is best known for the Portable Document Format (PDF), Flash player and Adobe Creative Suite, later Adobe Creative Cloud.


Vulnerability description :
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A reflected XSS is available in the get3.adobe.com sub-domain.
Through this vulnerability, an attacker could tamper with page rendering, redirect victims to fake Adobe portals, or capture Adobe's users credentials such cookies. 
It's also possible to forge a fake adobe's page with this XSS to provide a backdoored version of the flash plugin to users.
This reflected XSS is on GET "re" variable and is not properly sanitized before being used to his page.


Proof of Concept 1 :
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A non-persistent XSS (RXSS) in "re" GET param is available in the get3.adobe.com sub-domain.
Tested on Firefox 31.0.
 
After upgrading Flashplayer with auto-update agent on Windows, a page of adobe sub-domain is automatically opened.
This page is opened to check if the upgrade is successfully ; and return code of the auto-update agent is passed through "re" GET variable.
This numeric return code is reinjected into the JavaScript source-code of the page and can be crafted to make an XSS.
 
PoC:
 
https://get3.adobe.com/fr/flashplayer/completion/aih/?exitcode=1337&re=7331;alert(/Reflected XSS - Yann CAM @ASAfety - www.synetis.com/);&type=update&appid=200


Proof of Concept 2 :
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Session cookie can be retrive with this XSS.

PoC:

https://get3.adobe.com/fr/flashplayer/completion/aih/?exitcode=1337&re=7331;alert(document.cookie);&type=update&appid=200


Screenshots :
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- http://www.asafety.fr/data/20140829-adobe-xss01.png
- http://www.asafety.fr/data/20140829-adobe-xss02.png
- http://www.asafety.fr/data/20140829-adobe-xss04.png


Solution:
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Fixed by Adobe PSIRT.
 
 
Additional resources :
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- https://www.adobe.com/
- https://blogs.adobe.com/psirt/
- https://helpx.adobe.com/security/acknowledgements.html
- http://www.asafety.fr/actualites-news/contribution-adobe-injection-de-code-javascript-xss/
- http://www.synetis.com

 
Report timeline :
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2014-08-28 : Adobe PSIRT Team alerted with details and PoC.
2014-08-30 : Adobe response and issue number affected (2985).
2014-10-28 : Vulnerability not fixed, second email to get a status.
2014-10-28 : Adobe response : still working on this issue.
2014-12-05 : Vulnerability seems to be fixed, third email to get a status.
2014-12-05 : Adobe response : case 2985 closed and acknowledgement.
2014-12-08 : Public advisory

Credits :
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Yann CAM - Security Consultant @ Synetis | ASafety

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SYNETIS | ASafety
CONTACT: www.synetis.com | www.asafety.fr