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Bekijk Volledige Versie : Riched20.DLL attribute label buffer overflow vulnerability



Jie Dong
17/02/03, 16:36
================================================== =========================
=====
Security Defence Stdio vulnerability announcement [001]
Riched20.DLL attribute label buffer overflow vulnerability
URL:http:\\www.yoursft.com
Author: Thrkdev
finds date:2003年2月1日
Announce date:2003年2月14日

Affected system: Microsoft Windows 98
Microsoft Windows 2000
Microsoft Windows XP
Perhaps,this vulnerability was still in other operating
system, but untest .
EMAIL: Thkrdev@yoursft.com
------------------------------------------------------------------------
Technical description:
A buffer overflow vulnerability exists in riched20.dll,which can result
in the collapse
of the application program that use the corresponding function of the DLL
module, But it is
very difficult to have the effect of allowing an attacker to execute
commands on a user’s system.

This problem exists in the analysed RTF file code, and there is an
overflows when drawing
figure-string( such as the size of the character) in the file form .This
overflow seem not to
be used for executing commands.
The following RTFfile may result in illegal operation :
{\rtf1\ansi\ansicpg936\deff0\deflang1033\deflangfe 2052{\fonttbl{\f0
\fnil\fprq2\fcharset134 \'cb\'ce\'cc\'e5;}}
{\colortbl ;\red255\green0\blue255;}
\viewkind4\uc1\pard\cf1\kerning2\f0
\fs18121111111111111111111111111111111110000 www.yoursft.com\fs20\par
}
"\fs" was used for setting the size of the followingly
words "www.yoursft.com". when the figure-string
that set the size of the fonts exceeding 1024byte(>1024b) , it Will cause
the buffer overflow ;And when
exceeding 65536byte(>65536b) it will probably cause crashing the
application program.
This promblom Not only appear in the setting of "\fs" , other attribute
will have the same problem under
the similar situation. And this following RTF files Will also result in
operating illegally :
{\rtf1\ansi\ansicpg936\deff0\deflang1033\deflangfe 2052{\fonttbl{\f0
\fnil\fprq2\fcharset134 \'cb\'ce\'cc\'e5;}}
{\colortbl ;\red255\green0\blue255;}
\viewkind4\uc1\pard\cf1\kerning2\f0121111111111111 111111111111111111112222
\fs180 www.yoursft.com\fs20\par
}
The terrible thing is nowadays lots of software was affected by this
vulnerability. The attacker can send a
malicious message that include exploiting the vulnerability, then when you
read this message your program will be crashed.

------------------------------------------------------------------------
Security Defence Stdio is a software development / technological websites,
mainly developing NET security products ,
the software of Security Defence Stdio --Trojan Ender-- receives users'
extensive favorable comment

3APA3A
18/02/03, 17:12
Dear Jie Dong,

Can't reproduce it on riched20.dll v.3.0 (5.30.23.1200) under NT.

--Sunday, February 16, 2003, 4:30:50 PM, you wrote to bugtraq@securityfocus.com:


JD> The following RTFfile may result in illegal operation :
JD> {\rtf1\ansi\ansicpg936\deff0\deflang1033\deflangfe 2052{\fonttbl{\f0
JD> \fnil\fprq2\fcharset134 \'cb\'ce\'cc\'e5;}} {\colortbl
JD> ;\red255\green0\blue255;} \viewkind4\uc1\pard\cf1\kerning2\f0
JD> \fs18121111111111111111111111111111111110000
JD> www.yoursft.com\fs20\par } "\fs" was used for setting the size of


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Thor Larholm
21/02/03, 21:48
Since RTF files are opened and rendered automatically by Outlook Express and
Internet Explorer, this is remotely exploitable through mail and web.

I had some problems reproducing this on Windows 2000, anyone had better
luck?


Regards
Thor Larholm
PivX Solutions, LLC - Senior Security Researcher

Latest PivX research: Multi-Vendor Unreal Engine Advisory
http://www.pivx.com/press_releases/ueng-adv_pr.html


----- Original Message -----
From: "Jie Dong" <Thkrdev@yoursft.com>
To: <bugtraq@securityfocus.com>
Sent: Sunday, February 16, 2003 2:30 PM
Subject: Riched20.DLL attribute label buffer overflow vulnerability


>
>
>
================================================== =========================
> =====
> Security Defence Stdio vulnerability announcement [001]
> Riched20.DLL attribute label buffer overflow vulnerability
> URL:http:\\www.yoursft.com
> Author: Thrkdev
> finds date:2003年2月1日
> Announce date:2003年2月14日
>
> Affected system: Microsoft Windows 98
> Microsoft Windows 2000
> Microsoft Windows XP
> Perhaps,this vulnerability was still in other operating
> system, but untest .
> EMAIL: Thkrdev@yoursft.com
> ------------------------------------------------------------------------
> Technical description:
> A buffer overflow vulnerability exists in riched20.dll,which can result
> in the collapse
> of the application program that use the corresponding function of the DLL
> module, But it is
> very difficult to have the effect of allowing an attacker to execute
> commands on a user's system.
>
> This problem exists in the analysed RTF file code, and there is an
> overflows when drawing
> figure-string( such as the size of the character) in the file form .This
> overflow seem not to
> be used for executing commands.
> The following RTFfile may result in illegal operation :
> {\rtf1\ansi\ansicpg936\deff0\deflang1033\deflangfe 2052{\fonttbl{\f0
> \fnil\fprq2\fcharset134 \'cb\'ce\'cc\'e5;}}
> {\colortbl ;\red255\green0\blue255;}
> \viewkind4\uc1\pard\cf1\kerning2\f0
> \fs18121111111111111111111111111111111110000 www.yoursft.com\fs20\par
> }
> "\fs" was used for setting the size of the followingly
> words "www.yoursft.com". when the figure-string
> that set the size of the fonts exceeding 1024byte(>1024b) , it Will cause
> the buffer overflow ;And when
> exceeding 65536byte(>65536b) it will probably cause crashing the
> application program.
> This promblom Not only appear in the setting of "\fs" , other attribute
> will have the same problem under
> the similar situation. And this following RTF files Will also result in
> operating illegally :
> {\rtf1\ansi\ansicpg936\deff0\deflang1033\deflangfe 2052{\fonttbl{\f0
> \fnil\fprq2\fcharset134 \'cb\'ce\'cc\'e5;}}
> {\colortbl ;\red255\green0\blue255;}
> \viewkind4\uc1\pard\cf1\kerning2\f0121111111111111 111111111111111111112222
> \fs180 www.yoursft.com\fs20\par
> }
> The terrible thing is nowadays lots of software was affected by this
> vulnerability. The attacker can send a
> malicious message that include exploiting the vulnerability, then when you
> read this message your program will be crashed.
>
> ------------------------------------------------------------------------
> Security Defence Stdio is a software development / technological websites,
> mainly developing NET security products ,
> the software of Security Defence Stdio --Trojan Ender-- receives users'
> extensive favorable comment
>
>
>

Raistlin
24/02/03, 22:50
> Since RTF files are opened and rendered automatically by Outlook Express
and
> Internet Explorer, this is remotely exploitable through mail and web.

There are still unfixed buffer overflows (i.e. an <a href=""> overflow,
http://securenetwork.it/szanero/bug-oe-2.htm) that can be remotely triggered
to crash outlook express, so this is not really something new.

It simply seems that if a bug does not allow remote code execution, it is
not something worth MS attention.

Stefano "Raistlin" Zanero
System Administrator Gioco.Net
public PGP key block at http://gioco.net/pgpkeys

Marc Ruef
25/02/03, 18:38
In-Reply-To: <7353719955.20030218113659@SECURITY.NNOV.RU>

Hi!

>Can't reproduce it on riched20.dll v.3.0 (5.30.23.1200) under NT.

It seems that my Windows XP Professional with riched20.dll v3.0
5.30.23.1211 is not vulnerable too.

In http://www.securityfocus.com/bid/6874/discussion/ the following remark
can be found: "Some reports indicate that this vulnerability could not be
reproduced on riched20.dll v.3.0 (5.30.23.1200) running on Windows NT."

I think that this depends on v3.0 of riched20.dll. This version does not
seem to contain the bufferoverflow.

Bye, Marc

--
http://www.computec.ch