Microsoft Dynamic CRM 2016 - Cross-Site Scripting vulnerability

Hello Everyone,

Product: MS Dynamic CRM 2016
Vendor: Microsoft

Vulnerability type: Cross Site Scripting
Vulnerable version: MS Dynamic CRM 2016 SP1 and previous
Vulnerable component: SyncFilterPage.aspx
Report confidence: Confirmed
Solution status: Not fixed by Vendor, will not patch the vuln.
Fixed versions: -
Researcher credits: Gregory DRAPERI
Vendor notification: 2017-05-30
Solution date:
Public disclosure: 2016-07-01
Reference: https://remoteawesomethoughts.blogspot.com/2017/06/cross-site-scripting-vulnerability-in.html
CVE reference:
CVSSv3: 5.4 <https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N>

Vulnerability Details:
MS Dynamic CRM 2016 is CRM tool. So like all others Customer
Relationship Management (CRM) applications are here to manage
company's interaction with current and potential customers.There is a
specific web-page accessible to define filters. This webpage is
accessible without authentication so it is easy to check its
existence. The vulnerability in located in the webpage
"SyncFilterPage.aspx" that will interpret arbitrary JavaScript in case
this link is submitted.

The vulnerability might also be present on Microsoft Dynamic CRM in
the cloud. It has not been possible to gather an account to verify. If
someone can try or share with me an instance URL I would be more than
happy.

Risk:
The malicious script can access any cookies without a HTTPOnly flag or
other sensitive information retained by the browser and used with that
site. These scripts can even rewrite the content of the HTML page to
perform phishing attemps or perform actions on the behalf of the
logged user.

PoC:
http://X.X.X.X/_controls/EditFilterControl/SyncFilterPage.aspx?requiredFields=toto%22;}alert(document.cookie);function%20test(){var%20a=%22test

Timelines
I tried to reach out Microsoft several times but after their first
response seeming to say it was not a real vulnerability, I have not
received any responses.
30/05/2017: First email to secure@microsoft.com to disclose the vulnerability
30/05/2107: Answer from Microsoft asking for more details and pointing
to a link defining what Microsoft thinks is a vulnerability
(https://technet.microsoft.com/library/cc751383.aspx)
31/05/2017: Second email explaining why it is a vulnerability and
giving more details
02/06/2017: Third attempt to check if they need more details
06/06/2017: Fourth attempt to check if they need more details
16/06/2017: Fifth attempt to check if they need more details and
letting them know that it will be published in case they think it
won't be fixed
28/06/2017: Last attempt to check if they need more details and
letting them know that it will be published

Best,

Gregory