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RealNetworks products vulnerable to buffer overflow via specially crafted MBC file

Vulnerability Note VU#451556

Original Release Date: 2006-04-01 | Last Revised: 2006-04-24


Numerous RealNetworks products are vulnerable to a buffer overflow that may allow a remote attacker to execute arbitrary code on a vulnerable system.


RealNetworks RealPlayer

RealNetworks RealPlayer is a multimedia application that allows users to view local and remote audio/video content.

MBC Files

MBC files are used to for Mimio BoardCast audio sessions. More information on Mimio Boards is available on the Mimio website.

The Problem

Numerous RealNetworks products fail to properly validate MBC files allowing a buffer overflow to occur. By persuading a user to access a specially crafted MBC file with RealPlayer, a remote attacker may be able to execute arbitrary code.


A complete list of affected software is available in the RealNetwork Security Update for March 2006.


By convincing a user to open a specially crafted MBC file with RealPlayer, a remote, unauthenticated attacker can execute arbitrary code on a vulnerable system.


Patch RealPlayer
Apply the patches supplied in the RealNetwork Security Update for March 2006.

Disable RealPlayer in your web browser

An attacker may be able to exploit this vulnerability by embedding the crafted MBC file in a web page and convincing a user to access that page. Disabling RealPlayer in the web browser will eliminate this attack vector thereby reducing the chances of exploitation.

To disable RealPlayer in Microsoft Internet Explorer,disable the RealPlayer ActiveX control. In other web browsers, such as Mozilla Firefox, disable the RealPlayer plugin.

Vendor Information


RealNetworks, Inc. Affected

Updated:  March 31, 2006



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.



If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

Group Score Vector



This issue was reported in RealNetwork Security Update for March 2006. RealNetworks credits John Heasman of NGSSoftware, Greg MacManus of iDEFENSE Labs, and Sowhat of Nevis Labs with providing information about this vulnerability.

This document was written by Jeff Gennari.

Other Information

CVE IDs: CVE-2006-1370
Severity Metric: 8.52
Date Public: 2006-03-22
Date First Published: 2006-04-01
Date Last Updated: 2006-04-24 11:07 UTC
Document Revision: 19

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