INFORMATION BULLETIN

R-349: Apple Quicktime Vulnerability

[US-CERT Vulnerability Note VU#751808]

September 14, 2007 18:00 GMT


PROBLEM:	This vulnerability may allow an attacker to pass arbitrary commands to other applications.
PLATFORM:	Plugins in Internet Explorer, Safari, and Netscape-compatible browsers.
DAMAGE:	Allows remote code execution.
SOLUTION:	See below workaround.

VULNERABILITY ASSESSMENT:	The risk is MEDIUM. Allows remote code execution.

LINKS:
CIAC BULLETIN:	http://www.ciac.org/ciac/bulletins/r-349.shtml
ORIGINAL BULLETIN:	http://www.kb.cert.org/vuls/id/751808
CVE:

[***** Start US-CERT Vulnerability Note VU#751808 *****]

Vulnerability Note VU#751808

Apple QuickTime remote command execution vulnerability

Overview

Apple QuickTime contains a vulnerability that may allow an attacker to pass arbitrary commands to other applications.

I. Description

Apple QuickTime is a media player that is available for Microsoft Windows and Apple OS X. Apple QuickTime includes browser plugins for Internet Explorer, Safari, and Netscape-compatible browsers.

QuickTime includes the ability for developers to control how QuickTime movies are launched, what controls are displayed to the user, and other actions. To specify these parameters, developers can create QuickTime link (.qtl) files. QuickTime link files can be embedded in web pages and launched automatically when a user visits a website.

The qtnext parameter can be used in QuickTime link files to specify the url of a multimedia file to load and play. The multimedia file may be hosted on a web page or stored locally.

Apple QuickTime incorrectly determines the command line used to launch the default web browser on Microsoft Windows systems. Rather than using the ShellExecute method, QuickTime determines the default handler for .HTM files and then crafts its own command line for the registered application. Any protective flags in the registered file handler are stripped out by QuickTime.

Current proof-of-concept code targets systems where Mozilla Firefox is the default handler for .HTM files. Other applications are also affected by this vulnerability, although the impact may vary based on what command line parameters the application accepts.

II. Impact

By convincing a user to open a specially crafted QuickTime file, a remote, unauthenticated attacker may be able execute arbitrary commands on a vulnerable system.

III. Solution

We are currently unaware of a practical solution to this problem. Please consider the following workarounds.

Restrict access to QuickTime Movies

Until updates are available, administrators and users are encouraged to view only trusted QuickTime movies. Some web sites may allow users to upload QuickTime movies that exploit this vulnerability.

Workarounds for users

Using the NoScript Firefox extension to whitelist web sites that can run scripts and access installed plugins may may mitigate this vulnerability. See the NoScript FAQ for more information.

Workarounds for administrators
Proxy servers or intrusion prevention systems may be able to filter QuickTime files and partially mitigate this vulnerability. Note that this workaround is not likely to mitigate or stop all attack vectors.

Systems Affected

Vendor	Status	Date Updated
Apple Computer, Inc.	Vulnerable	13-Sep-2007

References

http://www.gnucitizen.org/blog/0day-quicktime-pwns-firefox
http://developer.apple.com/quicktime/quicktimeintro/tools/embed2.html
http://noscript.net/features#contentblocking
http://noscript.net
http://msdn2.microsoft.com/en-us/library/ms647732.aspx
http://support.microsoft.com/kb/224816

Credit

This vulnerability was disclosed by pdp on the GNUCITIZEN website.

This document was written by Ryan Giobbi and Will Dormann.

Other Information

Date Public	09/12/2007
Date First Published	09/13/2007 05:00:24 PM
Date Last Updated	09/13/2007
CERT Advisory
CVE Name
Metric	35.11
Document Revision	26




[***** End US-CERT Vulnerability Note VU#751808 *****]

CIAC wishes to acknowledge the contributions of US-CERT for the information contained in this bulletin.

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