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.

The application that you are running is blocked because the application does not comply with security guidelines implemented in Java 7 Update 51.

Contact the developer or publisher of this application and let them know about the application being blocked. You can refer them to these links that provide information about implementing secure practices in the code for the application.

• JAR File Manifest Attributes for Security
• Java SE Security Documentation
• Secure Coding Guidelines for the Java Programming Language

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.