Vulnerability Note VU#871673

RealPlayer playlist name stack buffer overflow

Overview

RealPlayer contains a stack buffer overflow in the handling of playlist names, which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.

I. Description

RealNetworks RealPlayer is a multimedia application that allows users to view local and remote audio/video content. The RealPlayer Database Component, which is provided by MPAMedia.dll, contains a stack buffer overflow in the handling of playlist names. The RealPlayer IERPCtl ActiveX control, which is provided by ierpplug.dll, can be used to import a local file into a specified playlist in RealPlayer. This can be used to trigger the buffer overflow vulnerability. The ActiveX control is present in RealPlayer version 9 (RealOne Player) and later.

II. Impact

By convincing a user to view a specially crafted HTML document (e.g., a web page or an HTML email message or attachment), a remote, unauthenticated attacker may be able to execute arbitrary code with the privileges of the user on a vulnerable system.

III. Solution

Apply an update

Please see the Security Update from RealNetworks. The update will provide newer versions of the RealPlayer Database Component for RealPlayer 10.5 and RealPlayer 11 beta. Users with RealOne Player, RealOne Player v2, or RealPlayer 10 should first update to RealPlayer 10.5 or later and then apply the security update.

Disable the IERPCtl ActiveX control in Internet Explorer

The ActiveX control that can be used as an attack vector can be disabled in Internet Explorer by setting the kill bit for the following CLSID:

{FDC7A535-4070-4B92-A0EA-D9994BCC0DC5}

More information about how to set the kill bit is available in Microsoft Support Document 240797. Alternatively, the following text can be saved as a .REG file and imported to set the kill bit for this control:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESOFTWAREMicrosoftInternet ExplorerActiveX Compatibility{FDC7A535-4070-4B92-A0EA-D9994BCC0DC5}]
"Compatibility Flags"=dword:00000400

Disable ActiveX

Disabling ActiveX controls in the Internet Zone (or any zone used by an attacker) appears to prevent exploitation of this and other ActiveX vulnerabilities. Instructions for disabling ActiveX in the Internet Zone can be found in the "Securing Your Web Browser" document.

Systems Affected

Vendor	Status	Date Updated
RealNetworks, Inc.	Vulnerable	20-Oct-2007

References

http://www.cert.org/tech_tips/securing_browser/#Internet_Explorer
http://service.real.com/realplayer/security/191007_player/en/
http://docs.real.com/docs/security/SecurityUpdate101907Player.pdf
http://www.securityfocus.com/bid/26130
http://www.symantec.com/enterprise/security_response/weblog/2007/10/realplayer_exploit_on_the_loos.html
http://support.microsoft.com/kb/240797
http://secunia.com/advisories/27248/

Credit

This vulnerability was analyzed and confirmed by US-CERT on October 13, 2007.

This document was written by Will Dormann.

Other Information

Date Public	10/18/2007
Date First Published	10/20/2007 10:25:17 AM
Date Last Updated	11/15/2007
CERT Advisory
CVE Name	CVE-2007-5601
Metric	34.02
Document Revision	23