COMMAND
zen
SYSTEMS AFFECTED
Win NT with zen 2.5 client (netware)
PROBLEM
Dave Cottle found following. Using the WINHLP32.EXE function for
providing help in the authentication boxes allows access to
resources without authentication through the help program's file
menu. The security issue is only relevant on WinNT workstations,
and only the latest version of the NetWare client (4.30.4.10) is
vulnerable.
This can be reproducible always by following method. At the logon
screen, or the locked workstation screen press ctl-alt-del to open
up the authentication box, use either the ? in the top right-hand
corner or press F1 to reveal the help program. Choose the
file->open option to reveal the explorer common dialog box. Either
open a help file that contains a link to cmd.exe (eg the WinNT
resource kit help files) or right-click on a folder and select
"open" to bring up a separate explorer window. Close down the
help function.
You will now have either a command prompt or an explorer window
without having to enter a usercode or password. If the workstation
is locked, you now have access to the current user's desktop, and
shoud also be active as the SYSTEM account. If there was no
logged-on user, you now have interactive access as the SYSTEM
account.
By this, NT client security can be bypassed, without requiring a
usercode or password.
SOLUTION
The Novell Client v4.3 for Windows NT that can currently be
downloaded from
http://www.novell.com/download
has been modified to prevent this from occurring. The patch file
NT430I1.EXE is also available on from same URL and contains the
updated code that prevents this issue as well as solves other
known issues with the 4.3 Client. The Z.E.N.works boxes that are
currently in the channel will all be rotated to incorporate the
updates. The best way for a customer to verify if they have the
Client that has this issue is to check the version of the files
LOGINW32.DLL in the WINNT\SYSTEM32 directory, and the LOGINW32.RLL
in the WINNT\SYSTEM32\NLS\ENGLISH. If the version of these files
is 2.00.00 then you could see this problem. If the version of the
files is anything later than 2.00.00, you have the files that
eliminate the problem. You can verify the version of the files by
right clicking on the files, going to properties and looking at
the File Version.