Re-release of Microsoft Security Bulletin MS99-046

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In November, we withdrew a previously released patch that improved the

randomness of TCP initial sequence numbers in Windows NT 4.0.  The patch was

withdrawn because it contained the same regression error that was present in

Windows NT 4.0 SP6.  We have eliminated the regression error and re-released

the patch.  The security bulletin has been updated and is available at

http://www.microsoft.com/Security/Bulletins/ms99-046.asp; the FAQ also has

been updated and is available at

http://www.microsoft.com/Security/Bulletins/ms99-046faq.asp.



All versions of the original patch were affected by the regression error,

although the error only manifested itself in certain situations.  When

applying the new patch, it's not necessary to uninstall the original patch

first.  Just install the patch as normal.  Here's how to determine which

patch to apply:

 - If you are running Windows NT 4.0 SP4 or SP5 on an Intel machine, go

   to http://www.microsoft.com/Downloads/Release.asp?ReleaseID=16763 and

   select q243835sp5i.exe.

 - If you are running Windows NT 4.0 SP6 on an Intel machine, go to

   http://www.microsoft.com/Downloads/Release.asp?ReleaseID=16764 and

   select q243835i.exe.

 - If you are running Windows NT 4.0 SP4 or SP5 on an Alpha machine, go

   to http://www.microsoft.com/Downloads/Release.asp?ReleaseID=16763 and

   select q243835sp5a.exe.

 - If you are running Windows NT 4.0 SP6 on an Alpha machine, go

   to http://www.microsoft.com/Downloads/Release.asp?ReleaseID=16764 and

   select q243835a.exe.



We are very sorry for any inconvenience caused by the regression error, and

will do our best to prevent similar problems in the future.  Regards,



The Microsoft Security Response Team