Note: This is an archival copy of Security Sun Alert 200255 as previously published on
Latest version of this security advisory is available from as Sun Alert 1000200.1.
Article ID : 1000200.1
Article Type : Sun Alerts (SURE)
Last reviewed : 2010-05-20
Audience : PUBLIC
Copyright Notice: Copyright © 2010, Oracle Corporation and/or its affiliates.

Security Vulnerability With Java Web Start (J2SE 5.0)


Release Phase

Bug Id

Date of Resolved Release

A vulnerability in Java Web Start

1. Impact

A vulnerability in Java Web Start may allow an untrusted application the ability to elevate its privileges. As a result, an application may grant itself permissions to read and write local files or execute local applications that are accessible to the user running the Java Web Start application.

Sun acknowledges, with thanks, Jouko Pynnonen for bringing this issue to our attention.

2. Contributing Factors

This issue can occur in Java Web Start in the following J2SE releases:

  • 1.4.2_06 and earlier 1.4.2 releases for Windows, Solaris and Linux

Note: Java Web Start in J2SE 5.0 and later and J2SE releases prior to 1.4.2 for Windows, Solaris and Linux are not affected by this issue. Java Web Start 1.0.1_02 and earlier are also not affected.

To determine the version of Java on a system, run the following command:

    % java -fullversion
java full version "1.4.2_06-b01"

3. Symptoms

There are no reliable symptoms that would indicate the described issue has been exploited.

4. Workaround

To work around the described issue, disable Java Web Start applications from being launched from a web browser as follows:

For Internet Explorer:

  1. Right click on the "Start" button and select "Explore"
  2. In the "Start Menu" window, select "Tools" => "Folder Options"
  3. From the "Folder Options" window, select the "File Types" tab
  4. From the "Registered File Types" window, scroll down and locate the "JNLP - JNLP File"
  5. Select the "JNLP - JNLP File" and click the "Delete" button

For Mozilla:

  1. Select "Preferences" under the browser's "Edit" menu
  2. In the "Preferences" window, select "Helper Applications" located under the "Navigator" category
  3. Under "Files types", scroll down and locate "application/x-java-jnlp-file"
  4. Select "application/x-java-jnlp-file" and click the "Remove" button


1. On Microsoft Windows, applications may also be launched from the desktop icon or Start Menu if a shortcut was previously created for an application. Unknown applications should not be launched through the desktop icon or the Start Menu. Shortcuts can be removed by using the Java Web Start Application Manager through the "Application/Remove Shortcut" menu item. For more information, see:


2. It is also possible to launch applications through the command line in Windows, Solaris, and Linux. Unknown applications should not be launched through the command line. Sites may consider renaming the Java Web Start launcher ("javaws.exe" for Windows and "javaws" for Solaris and Linux) to prevent Java Web Start from launching.

The launcher can be found at:


C:\Program Files\java\j2re1.4.2\javaws\javaws.exe

Solaris (if installed using pkg):


Linux (if installed using rpm):


5. Resolution

This issue is addressed in Java Web Start in the following J2SE releases:

  • 1.4.2_07 or later for Windows, Solaris and Linux

J2SE releases are available for download at the following links:

  • J2SE 5.0 Update 2 at: and
  • J2SE 1.4.2_07 at:

Note: It is recommended that affected versions be removed from your system. For more information, please see the installation notes on the respective download pages.

This Sun Alert notification is being provided to you on an "AS IS" basis. This Sun Alert notification may contain information provided by third parties. The issues described in this Sun Alert notification may or may not impact your system(s). Sun makes no representations, warranties, or guarantees as to the information contained herein. ANY AND ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT, ARE HEREBY DISCLAIMED. BY ACCESSING THIS DOCUMENT YOU ACKNOWLEDGE THAT SUN SHALL IN NO EVENT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES THAT ARISE OUT OF YOUR USE OR FAILURE TO USE THE INFORMATION CONTAINED HEREIN. This Sun Alert notification contains Sun proprietary and confidential information. It is being provided to you pursuant to the provisions of your agreement to purchase services from Sun, or, if you do not have such an agreement, the Terms of Use. This Sun Alert notification may only be used for the purposes contemplated by these agreements.

Copyright 2000-2010 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, CA 95054 U.S.A. All rights reserved.

Java Web Start 1.0

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