iDefense Security Advisory 02.01.10
http://labs.idefense.com/intelligence/vulnerabilities/
Feb 01, 2010

I. BACKGROUND

RealPlayer is an application for playing various media formats,
developed by RealNetworks Inc. Since late 2003, Real Player has been
based on the open-source Helix Player. More information can be found at
the URLs shown. For more information, see the vendor's site found at the
following links.

http://www.real.com/realplayer.html
http://helixcommunity.org/

II. DESCRIPTION

Remote exploitation of an integer overflow vulnerability in RealNetworks
Inc.'s Real Player could allow an attacker to execute arbitrary code
with the privileges of the current user.

This problem specifically exists in the CMediumBlockAllocator::Alloc
method. When calculating the size of a memory allocation, an integer
overflow occurs. This leads to heap corruption, which can result in the
execution of arbitrary code.

III. ANALYSIS

Exploitation of this vulnerability results in the execution of arbitrary
code with the privileges of the user executing Real Player.

To be successful, an attacker must persuade a user to use Real Player to
view specially crafted media. This could be accomplished via a Web page
or direct link to the malicious media.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in Real
Player versions 10.5 (build 6.0.12.883) and 11 (build 6.0.14.738) on
Windows. Other versions may also be affected. RealNetworks has provided
the following matrix of vulnerable products:

Windows RealPlayer 11.0.0 - 11.0.4
Windows RealPlayer 10.5
(6.0.12.1040-6.0.12.1663, 6.0.12.1698, 6.0.12.1741)
Mac RealPlayer 10
Linux RP10

V. WORKAROUND

iDefense is currently unaware of any effective workaround for this
issue.

VI. VENDOR RESPONSE

RealNetworks has released a patch which addresses this issue.
Information about downloadable vendor updates can be found by clicking
on the URLs shown.

http://service.real.com/realplayer/security/01192010_player/en/

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2009-4248 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

01/11/2008  Initial Contact
01/11/2009  Initial Response
02/01/2010  Coordinated public disclosure.

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright © 2010 iDefense, Inc.

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
 There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct,
indirect, or consequential loss or damage arising from use of, or
reliance on, this information.