RE: MS-DOS Filename/Directory Vulnerability

["Troy Murray" <murrayt5 () msu edu>]

Hive: HKEY_LOCAL_MACHINE\SYSTEM
Key:  \CurrentControlSet\Control\FileSystem
Name: NtfsDisable8dot3NameCreation
Type: REG_DWORD
Value: 1 (turns off 8.3 name generation, only 16 bit need).

===========================================
Troy D. Murray
Microcomputer Hardware/Software Coordinator
Michigan State University
College of Human Medicine
Department of Medicine
Immunohematology & Serology Lab
B228 Life Science
East Lansing, MI  48824-1034
(P) 517-432-3545
(F) 517-353-5436
(E) murrayt5 () msu edu


-----Original Message-----
From: Seth Arnold [mailto:sarnold () wirex com] 
Sent: Thursday, August 16, 2001 7:32 PM
To: bugtraq () securityfocus com
Subject: Re: MS-DOS Filename/Directory Vulnerability


On Thu, Aug 16, 2001 at 07:08:16PM -0700, Felipe Moniz wrote:
> I tested this in the PWS (based on IIS 4) and it worked.
>
> I created a file called "clientlist2001.txt" and with client~1.txt
> (www.site.com/client~1.txt) I get the clientlist2001.txt without know 
> the complete name of the file. The problem occurs also when I type 
> "postin~1.htm" for access "postinfo.html" file.

This is a known problem. There is a switch that can be thrown somewhere
(possibly only in the registry, but I thought I have seen a checkbox for
this somewhere...) that does not generate the MSDOS names on NTFS
partitions.

Microsoft has written a guide to securing WinNT; I bet they have updated
it for Win2k as well. They detail how to turn off the MSDOS filename
support in that document.

Cheers!