COMMAND
"OffloadModExpo Registry Permissions"
SYSTEMS AFFECTED
- Microsoft Windows NT 4.0 Workstation
- Microsoft Windows NT 4.0 Server
- Microsoft Windows NT 4.0 Server, Enterprise Edition
- Microsoft Windows NT 4.0 Server, Terminal Server Edition
PROBLEM
Following is based on a Security Bulletin from the Microsoft.
This vulnerability involves a registry key used by the CryptoAPI
Base CSPs to specify the driver DLL for a hardware accelerator.
By design, such a DLL would have access to users' public and
private keys. Although only administrators should have permission
to add such a DLL, the permissions on the key actually would allow
any user who could interactively log onto the machine to do so.
By writing a bogus DLL and installing it, a malicious user could
compromise the keys of other users who subsequently used the
machine.
The machines primarily at risk would be workstations and terminal
servers. If normal security recommendations are followed, normal
users will not be allowed to interactively log onto domain
controllers, web servers, database servers, ERP servers, and other
security-critical machines. Windows NT auditing could be used to
determine who changed the key's value. A tool is available that
resets the permissions on the affected key to the correct default
values. In addition, it incorporates the functionality of the
tool provided in Microsoft Security Bulletin MS00-008.
Microsoft thanks Sergio Tabanelli and Banca Nazionale del Lavoro
for reporting this vulnerability to MS and working with them to
protect customers.
SOLUTION
Windows 2000 is not affected by this vulnerability. Patch
availability:
- X86: http://www.microsoft.com/Downloads/Release.asp?ReleaseID=20330
- Alpha: http://www.microsoft.com/Downloads/Release.asp?ReleaseID=20331