Setting the Security Level of the Java Client

Contents

Ensuring the Most Secure JRE
Disabling Java in the Browser
Setting the Security Level of Unsigned Apps
Security Options for Trusted Signed or Self-Signed Apps
Install Options
Apps with Mixed Code

As of the JDK 7u10 release, a user may control, via the Java Control Panel, the level of security that will be used when running unsigned (also called "untrusted" or "sandboxed") Java apps in a browser. The user may select from five levels of security, including disabled, where no apps are allowed to run in the browser.

These security levels apply to running Java in the browser, which includes plugin applets, Java Web Start applications, embedded JavaFX applications, and access to the native deployment toolkit plugins. Setting the security level does not affect stand alone applications. Note that applets and these various types of applications are collectively referred to as apps or Java apps.

Ensuring the Most Secure JRE

Before the browser plugin software attempts to run a Java app, it verifies that the JRE version is at or above the security baseline for that family and that the age of the JRE is recent. If the JRE is deemed expired or insecure, additional security warnings are displayed. In most of these dialogs, the user has the option to block running the app, to continue running the app, or to go to java.com to download the latest release.

Disabling Java in the Browser

For installations where the highest level of security is required, it is possible to entirely prevent any Java apps (signed or unsigned) from running in a browser by de-selecting Enable Java content in the browser in the Java Control Panel under the Security tab.

Setting the Security Level of Unsigned Apps

Note: These settings affect all browsers that use Oracle's Java browser plug-in. They do not affect desktop (also called stand alone) Java apps.

A Security Level slider has been added to the Java Control Panel (under the Security tab) to control the behavior when attempting to run unsigned apps (either from the web or local). The user can select low, medium, high or very high security settings. There are fewer security warnings at the lowest setting. While it is called the "Security Level control" (or slider), it can be thought of as the ability to control the level of notification you will receive when the browser attempts to run unsigned Java apps.

The following list summarizes the behavior of the different levels:

Low

Most unsigned Java apps in the browser will run without prompting unless they request access to a specific old version or to protected resources on the system.
Medium

Unsigned Java apps in the browser will run without prompting only if the Java version is considered secure. (The JRE version should be at or above the latest security update release of Java from Oracle.) You will be prompted if an unsigned app requests to run on an old version of Java. To download the latest version of Java, go to java.com.
High

You will be prompted before any unsigned Java app runs in the browser. If the JRE is below the security baseline, you will be given an option to update.
Very High

Unsigned (sandboxed) apps will not run.

The default security level is High.

Additionally, there are two checkboxes available in the Java Control Panel (under the Advanced tab) that are relevant to unsigned apps:

Show sandbox warning banner
Disables the warning icon that appears next to top level windows opened from an unsigned app.
Allow user to accept JNLP security requests

Allows an unsigned app that is deployed via JNLP to ask the user for increased access to computer resources like the hard drive or the printer.

Security Options for Trusted Signed or Self-Signed Apps

Note that the security options for trusted signed and self-signed apps has not changed in the 7u10 release. These options were available prior to the 7u10 release.

To select the behavior when attempting to run trusted signed or self-signed apps, there are several checkboxes available in the Java Control Panel (under the Advanced tab):

Allow user to grant permissions to signed content
Allow user to grant permissions to content from an untrusted authority
Don't prompt for client certificate selection when no certificates or only one exists
Warn if site certificate does not match hostname
Show site certificate even if it is valid

Install Options

In the JDK 7u10 release, new arguments for command line installation support setting the security level for Java in the browser. Admin privileges are required to install the JRE. Note that, in the 7u10 timeframe, these arguments are available only on Microsoft Windows.

On installation, the WEB_JAVA argument has the following effect:

WEB_JAVA=1 enables Java in the browser

WEB_JAVA=0 disables Java in the browser
On installation, the WEB_JAVA_SECURITY_LEVEL argument has the following effect:

WEB_JAVA_SECURITY_LEVEL=VH sets the security level to very high

WEB_JAVA_SECURITY_LEVEL=H sets the security level to high

WEB_JAVA_SECURITY_LEVEL=M sets the security level to medium

WEB_JAVA_SECURITY_LEVEL=L sets the security level to low

After installation of the JRE, verify the security level settings in the Java Control Panel.

Apps with Mixed Code

This information also applies to untrusted apps that have signed trusted extensions, but not to signed trusted apps that have unsigned unstrusted extensions. For more information, see Mixing Signed and Unsigned Code.