Vulnerability Development mailing list archives

Outlook 2000 and maybe others contain begin 666 filename.exe or filename.whatever


From: "Adonis.No.Spam" <adonis1 () videotron ca>
Date: Sun, 24 Mar 2002 08:07:37 -0500

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                          /    NtWaK0 Bugs  \
+-----------------------------------------------------------------------.
Affected         : Outlook 2000 and maybe others                        :
Type             : Create any file type by sending a body message that  :
                 : contain begin 666 filename.exe or filename.whatever  :
Date             : 23-03-2002                                           :
Author           : NtWaK0 @ www.SafeHack.com                            :
+-----------------------------------------------------------------------.

+----------------------------------.
 Create Attachement Using begin 666 \
+------------------------------------`----------------------------------.
+-----------.                                                           :
 Disclaimer  \                                                          :
+-------------`---------------------------------------------------------.
The information in this advisory is believed to be true based on        :
experiments though it may be false. The opinions expressed in this      :
advisory and program are my own and NOT of any company.                 :
In Fact I do not work for no one at the present time.                   :
                                                                        :
This material is presented for informational and entertainment purposes :
only, and to satisfy the curious. Any activities described in this file :
which involve vandalism, theft, or any other illegal activities are     :
recounted from third-party conversations. I do not condone or encourage :
vandalism or theft. I do not accept any liability for anything anyone   :
does with this information.                                             :
Remember: Use a computer in ways that ensure respect for your fellows.  :
                                                                        :
+-------.                                                               :
 T.O.C.  \                                                              :
+---------`-------------------------------------------------------------.
                                                                        :
                                                                        :
   [  Brief History . . . . . . . . . . . . . . . . . . . . . .line 47 ]:
                                                                        :
   [  The Problem . . . . . . . . . . . . . . . . . . . . . . .line 82 ]:
                                                                        :
   [  The Solution . . . . . . . . . . . . . . . . . . . . . .line 195 ]:
                                                                        :
+-------------.                                                         :
 Brief History \                                                        :
+---------------`-------------------------------------------------------.
Follow up on the first post.                                            :
                                                                        :
After testing a bit more the beging uucode. I found that not only       :
begin 666 will create an attachement file But any header that follow    :
uucode standard.                                                        :
                                                                        :
I have attacked an extract of uucode defenition below.                  :
                                                                        :
The body of the message start with the word "begin 666" followed by     :
any filename you like to create.                                        :
This sequence of characters is identical to that of the header for a    :
file attachment that is encoded in UUencode format.                     :
                                                                        :
                                                                        :
For this reason, the message is incorrectly interpreted as an encoded   :
attachment.                                                             :
                                                                        :
This problem only occurs in messages that you receive in plain text     :
format.                                                                 :
                                                                        :
This problem maybe occurs in Microsoft Outlook express too I did not    :
test it... I am going to do more tests using the begin something.       :
                                                                        :
This can lead to bigger problem. I just hope that microsoft work on it  :
whenever they can.                                                      :
But if one line message body can create an attachement this of course   :
does not lead to a SECURE mail client.                                  :
                                                                        :
                                                                        :
                                                                        :
+---------------------------+                                           :
Test OS Applications <<<                                           :
+---------------------------+                                           :
Tested on Windows 2K with outlook 2000 and patchs                       :
                                                                        :
+-----------.                                                           :
 The Problem \                                                          :
+-------------`---------------------------------------------------------.
The body of the message starts with the word "begin" followed by one    :
space and the application that you like to RUN.                         :
                                                                        :
I have tried begin and two spaces and this did not lead to attachement  :
creation. As mentioned in at MS site at the following URL:              :
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q265230         :
                                                                        :
But I was able to create attachement by sending begin 666 filename.exe  :
See detail below.                                                       :



[Extracted From http://www.fht-esslingen.de/~clfuit00/sasnt/uucode/ ]
UUENCODE(5)

NAME
       uuencode - format of an encoded uuencode file

DESCRIPTION
       Files output by uuencode(1) consist of a header line, fol­
       lowed by a number of body lines, and a trailer line.   The
       uudecode(1)  command  will  ignore any lines preceding the
       header or following the trailer.  Lines preceding a header
       must not, of course, look like a header.

       The  header  line  is  distinguished by having the first 6
       characters begin  The word begin is followed by a mode (in
       octal), and a string which names the remote file.  A space
       separates the three items in the header line.

       The body consists of a number of lines, each  at  most  62
       characters  long  (including the trailing newline).  These
       consist of a character count, followed by encoded  charac­
       ters,  followed  by  a  newline.  The character count is a
       single printing character, and represents an integer,  the
       number  of  bytes  the  rest of the line represents.  Such
       integers are always in the range from 0 to 63 and  can  be
       determined  by  subtracting the character space (octal 40)
       from the character.

       Groups of 3 bytes are stored in 4 characters, 6  bits  per
       character.   All are offset by a space to make the charac­
       ters printing.  The last line may be shorter than the nor­
       mal  45  bytes.   If the size is not a multiple of 3, this
       fact can be determined by the value of the  count  on  the
       last  line.   Extra  garbage  will be included to make the
       character count a multiple of 4.  The body  is  terminated
       by a line with a count of zero.  This line consists of one
       ASCII space.

       The trailer line consists of end on a line by itself.

SEE ALSO
       uuencode(1), uudecode(1), uusend(1), uucp(1), mail(1)

HISTORY
       The uuencode file format appeared in BSD 4.0 .

                                                                        :
    ================                                                    :
Proof-Of-Concept <<<                                                :
    ================                                                    :
                                                                        :
Test # 00                                                               :
=========                                                               :
Send your self a mail with a subject whatever you like.                 :
In the body type: begin 666 notepad.exe                                 :
Click Send                                                              :
                                                                        :
Check your mail. Now you should have a mail with ATTACHEMENT.           :
The attackement will be NOTEPAD.EXE.                                    :
                                                                        :
If you have your outlook set to stop .exe that mail will be rejected    :
and you will get "Outlook has blocked access to Notepad.exe.            :
                                                                        :
I have no idea why the file was Created. I just used normal text :).    :
                                                                        :
Test # 01                                                               :
=========                                                               :
I have done another test with a message body:                           :
begin 666 testtttttttttttttttttttttttttttttt.txt                        :
This will create a file called testtttttttttttttttttttttttttttttt.txt.  :
as attachement. The file is empty if you try to open it.                :
                                                                        :
Test # 02                                                               :
=========                                                               :
I created a file mail with a message body:                              :
begin 666 testttttttttttttttttttttttttttttttttttttttttttttttttttttttttt-:
tttt.txt                                                                :
                                                                        :
This did not create an attachment So their is a limite to the text      :
size.                                                                   :
                                                                        :
Test # 03                                                               :
=========                                                               :
begin 666 testttttttttttttttttttttttttttttttttttttttttttttttttttttttttt-:
tt.txt                                                                  :
This created an attachement with a filename :                           :
testttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt.txt     :
                                                                        :
Imagine someone spam your mail server with Only one line body message   :
example begin 666 virus.exe                                             :
I am not sure if your ANTI-VIRUS protection wont be over-Booked.        :
                                                                        :
This bug is similar to but not the Same AT ALL.                         :
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q265230         :
                                                                        :
+------------.                                                          :
 The Solution \                                                         :
+--------------`--------------------------------------------------------.
This mail was sent to the Vendor too (Microsoft)                        :
+-----------------------------------------------------------------------.

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________________________________________________________________________
The only secure computer is one that's unplugged, locked in a safe,
and buried 20 feet under the ground in a secret location... and i'm
not even too sure about that one"--Dennis Huges, FBI.
____________________________________________________________.___________
Live Well Do Good  www.SafeHack.com                         |
Je Pense, Donc Je Suis                                    \(|)/
                                                         --(")--
                                                           /`\  NtWaK0
________________________________________________________________________
________________________________________________________________________
-=- Use a computer in a ways that ensure respect for your fellow     -=-


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