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McAfee VirusScan Enterprise security restrictions bypass



Security Advisory 			@ Mediaservice.net Srl
(#01, 13/04/2016)	  		Data Security Division

         Title:	McAfee VirusScan Enterprise security restrictions bypass
   Application:	McAfee VirusScan Enterprise 8.8 and prior versions
      Platform:	Microsoft Windows
   Description:	A local Windows administrator is able to bypass the
		security restrictions and disable the antivirus engine
		without knowing the correct management password
        Author:	Maurizio Agazzini <inode@xxxxxxxxxxxxxxxx>
 Vendor Status: Fixed
    References: http://lab.mediaservice.net/advisory/2016-01-mcafee.txt
                http://lab.mediaservice.net/code/mcafee_unprotector.c

1. Abstract.

McAfee VirusScan Enterprise has a feature to protect the scan engine
from local Windows administrators. A management password is needed to
disable it, unless Windows is running in "Safe Mode".

From our understanding this feature is implemented insecurely: the
McAfee VirusScan Console checks the password and requests the engine to
unlock the safe registry keys. No checks are done by the engine itself,
so anyone can directly request the engine to stop without knowing the
correct management password.

2. Example Attack Session.

The attack can be reproduced in different ways, here are some examples.

Example 1:

Open the McAfee VirusScan Console and Sysinternals Process Explorer.

Under Process Explorer:

- Locate the mcconsol.exe process
- Type CTRL+L (show lower pane)
- Search for all "HKLM\SOFTWARE\McAfee\DesktopProtection" keys
- Close all the handles of this registry key

Go back to the McAfee Console and:

- Go to: Tools -> General Options
- Select the "Password Options" tab
- Select "No password" and apply settings

Now it is possible to stop the antivirus engine.

Example 2:

A specific tool has been written to request to disable password
protection. After running the tool you can disable it via the VirusScan
Console.

Code: http://lab.mediaservice.net/code/mcafee_unprotector.c

3. Affected Platforms.

All McAfee Viruscan Enterprise versions prior to 8.8 without SB10151 are
affected. Exploitation of this vulnerability requires that an attacker
has local Windows administrator privileges.

4. Fix.

On 25 February 2016, version SB10151 hotfix has been relased by McAfee,
which fixes the described vulnerability.

https://kc.mcafee.com/corporate/index?page=content&id=SB10151

5. Proof Of Concept.

See Example Attack Session above.

6. Timeline

07/11/2014 - First communication sent to McAfee
17/11/2014 - Second communication sent to McAfee
17/11/2014 - McAfee: Request to send again vulnerability information
18/11/2014 - Sent vulnerability information and PoC again
11/12/2014 - McAfee: Problem confirmed
09/03/2015 - Request for update to McAfee
06/05/2015 - Request for update to McAfee
06/05/2015 - McAfee: Patch release planned for Q3
20/08/2015 - McAfee: Request for deadline delay (31/03/2016)
25/02/2016 - McAfee: SB10151 patch has been relased

Copyright (c) 2014-2016 @ Mediaservice.net Srl. All rights reserved.

-- 
Maurizio Agazzini                     CISSP, CSSLP, OPST
Senior Security Advisor
@ Mediaservice.net Srl                Tel: +39-011-32.72.100
Via Santorelli, 15                    Fax: +39-011-32.46.497
10095 Grugliasco (TO) ITALY           http://mediaservice.net/disclaimer

"C programmers never die. They are just cast into void"