A buffer overflow vulnerability in the Java Web Start URL parsing code may allow an untrusted application to elevate its privileges. For example, an application may grant itself permissions to read and write local files or execute local applications with the privileges of the user running the Java Web Start application.

Sun acknowledges with thanks, Brett Moore of Security-Assessment.com for discovering and reporting this issue.

Sun also acknowledges eEye Digital Security for bringing this issue to our attention.

This issue can occur in the following releases (for Windows, Solaris, and Linux):

• Java Web Start in JDK and JRE 6 Update 1 and earlier
• Java Web Start in JDK and JRE 5.0 Update 11 and earlier

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

    % java -version

Note: Java Web Start in SDK and JRE 1.4.x are not affected by this issue.

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

To reduce the likelihood of executing untrusted applications which may allow this issue to be exploited, Java Web Start applications may be disabled temporarily (until the updates or patches have been installed) as follows:

For Internet Explorer (Windows):

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

Note 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:

http://java.sun.com/j2se/1.5.0/docs/guide/javaws/developersguide/overview.html#jws

Note 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:

Windows:

C:\Program Files\java\j2re1.5.0\javaws\javaws.exe

Solaris (if installed using pkg):

/usr/bin/javaws

Linux (if installed using rpm):

/usr/java/jre1.5.0/bin/javaws

This issue is addressed in the following releases (for Windows, Solaris, and Linux):

• Java Web Start in JDK and JRE 6 Update 2 or later
• Java Web Start in JDK and JRE 5.0 Update 12 or later

Java SE 6 is available for download at the following links:

http://java.sun.com/javase/downloads/index.jsp

Java SE 6 Update 2 for Solaris is available in the following patches:

• Java SE 6: update 2 (as delivered in patch 125136-02 or later)
• Java SE 6: update 2 (as delivered in patch 125137-02 or later (64bit))
• Java SE 6_x86: update 2 (as delivered in patch 125138-02 or later)
• Java SE 6_x86: update 2 (as delivered in patch 125139-02 or later (64bit))

J2SE 5.0 is available for download at the following link:

http://java.sun.com/j2se/1.5.0/download.jsp

J2SE 5.0 Update 12 for Solaris is available in the following patches:

• J2SE 5.0: update 12 (as delivered in patch 118666-12 or later)
• J2SE 5.0: update 12 (as delivered in patch 118667-12 or later (64bit))
• J2SE 5.0_x86: update 12 (as delivered in patch 118668-12 or later)
• J2SE 5.0_x86: update 12 (as delivered in patch 118669-12 or later (64bit))

Note: When installing a new version of the product from a source other than a Solaris patch, it is recommended that the old affected versions be removed from your system. To remove old affected versions on the Windows platform, please see:

http://java.com/en/download/help/uninstall_java.xml

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