Java has further enhanced security to make the user system less vulnerable to external exploits. Starting with Java 7 Update 51, Java does not allow users to run applications that are not signed (unsigned), self-signed (not signed by trusted authority) or that are missing permission attributes.
Risks involved in running applications
- Unsigned application
An application without a certificate (i.e. unsigned apps), or missing application Name and Publisher information are blocked by default. Running this kind of application is potentially unsafe and present higher level of risk.
- Self-signed application (Certificate not from trusted authority)
An application with self-signed certificate is blocked by default. Applications of this type present the highest level of risk because publisher is not identified and the application may be granted access to personal data on your computer.
- Jar file missing Permission Attribute
Permissions Attribute verifies that the application requests the permission level that developer specified. If this attribute is not present, it might be possible for an attacker to exploit a user by re-deploying an application that is signed with original certificate and running the application at a different privilege level.
It is highly recommended not to run these types of applications. However if you still want to run these apps, run only if you understand the risks and implications.
As a workaround, you can use the Exception Site list feature to run the applications blocked by security settings. Adding the URL of the blocked application to the Exception Site list allows it to run with some warnings.
Steps to Add URLs to the Exception Site list
- Go to the Java Control Panel (On Windows Click Start and then Configure Java)
- Click on the Security tab
- Click on the Edit Site List button
- Click Add in the Exception Site List window
- Click in the empty field under the Location field to enter the URL
(URL should begin with http:// or https://)
If the URL where the applet is hosted is different from the URL of the web page from which the applet is launched, then you will need to add both the URL for the applet as well as the URL for the web page.
Example with different URLs for the applet and the web page
For Yahoo games Checkers, you would enter both URLs (The urls listed can be different depending on which host is serving the game)
This is the url for the Yahoo games domain
This is the url where the game is hosted and shown in the dialog box for the blocked application
- Click OK to save the URL that you entered
- Click Continue on the Security Warning dialog