Re: WinNews Special Issue (fwd)

[Rich Graves <llurch@networking.stanford.edu>]

On Sat, 21 Oct 1995, Tim Philp wrote:

> I am on a Microsoft mailing list that is for developers of Win95 stuff. 
> Today I found this in my mailbox. This file details a security bug in 
> Win95 that I thought might be interesting to the group.
> Regards, 
> 
> Tim Philp
> Brantford, Ontario,
> Canada
...
> ---------- Forwarded message ----------
> Date: Fri, 20 Oct 1995 17:15:33 -0700
> From: WinNews@Microsoft.com
> To: WinNews@microsoft.nwnet.com
> Subject: WinNews Special Issue
> 
> UPDATED DRIVERS FOR WINDOWS 95 FILE AND PRINTER SHARING 
> SECURITY ISSUE - October 20, 1995
> 
> Microsoft wants its customers to know that it has
> discovered and fixed a potential security problem with file
> and printer sharing in Windows 95.  Only customers who have

What a fucking joke. The Samba development community told Microsoft about
this in *January*. Microsoft's fix for the same problem in Windows for
Workgroups is dated September 28. 

> enabled file and printer sharing - a non-default option -
> may have been at risk, and, to the best of our knowledge,
> no users have been harmed.

They must not have asked anybody, then.

> What are the issues? 
> File and Printer Sharing for NetWare Networks
> 
> Microsoft was recently made aware of an issue with File
> and Printer sharing for NetWare Networks which may affect
> data security for corporate users.
> 
> Only users whose environments meet both of the following
> conditions may be affected:
> 
>     1. They configure their machine to share files and
>         printers with other users on the network using File
>         and Printer Sharing for NetWare networks (This
>         option is not turned on by default)
>     2. They enable remote administration or install
>         Microsoft Remote Registry Services  (These options
>         are not turned on by default)

#2 is not actually required.

> If your configuration matches that listed above, it is
> possible for another user on the network to gain read-only
> access to your machine after the administrator has logged
> off the machine and until you restart your computer.  To
> correct this problem, Microsoft has issued an updated
> driver for File and Printer Sharing for NetWare Networks.
> The updated driver ensures that only valid administrators
> have access to the computer's drive.

Good for them.

Microsoft is also investigating a bug where you can map whole unshared
drives over IPX or SMB. Maybe they'll acknowledge the problem in February.

> File and Printer Sharing for Microsoft Networks (not MSN:
>     The Microsoft Network online service)
> 
> Microsoft is also issuing an update for a known problem
> with File and Printer Sharing for Microsoft Networks and a
> certain UNIX shareware network client (Samba's SMBCLIENT).
> The update corrects a problem with share-level security
> documented in the Microsoft Knowledge Base on October 9th.

This is incorrect. The acknowledgement of the bug, which was pointed out
to Microsoft in January, was not available until October 12. 

> The Samba SMB client allows its users to send illegal
> networking commands over the network. The Samba client is
> the only known SMB client at this time that does not filter
> out such illegal commands.  SMBCLIENT users do not
> automatically have access to the Windows 95 drive, and
> must know the exact steps to send these illegal commands.

I wonder what illegal commands they're talking about. All you have to do 
is "cd ..". The problem is that Microsoft assumed that anyone using SMB 
was mapping a drive on a WinTel box, and thus couldn't cd below root. They
provided no mechanism on the server end to ensure that this didn't 
happen.

The problem was not limited to SMB over TCP/IP; Samba was merely the only 
radily available software to (inadvertently) expose the problem.

> The updated driver prevents these illegal commands from
> being executed, preventing SMBCLIENT users from accessing
> the drive on which sharing is enabled.  With the updated
> driver, the SMBCLIENT user will only have access to those
> shared folders that the Windows 95 user has designated.

What a novel security feature. I am so glad that Microsoft came up with this.

> How do I get the Updated Drivers?
> (Please note that this only affects English language 
> versions of Windows 95.) 

Yup, they won't install on other language versions. So they're still 
vulnerable.

> Both drivers are available for immediate download from the
> Internet (http://www.microsoft.com/windows), The Microsoft

Specifically, http://www.microsoft.com/windows/software/updates.htm.

> Microsoft is committed to providing safe connectivity
> solutions for customers.  Microsoft takes this
> responsibility seriously and has worked, and will continue
> to work, with great speed to provide solutions for
> customer issues.   

Yes. Tell them about a huge, stoopid bug in January, and they will
acknowledge the bug in mid-October. In the meantime, they will directly 
lie to the press and users about it.

-rich