This application will be blocked in a future Java security update because the JAR file manifest does not contain the Permissions attribute. Please contact the Publisher for more information.

UPDATED: 17 October 2013
Applet security

The new Java update "1.7.0_45" shows permission warning in applet. If you want to get rid of that warning you must have MANIFEST.MF file in your applet/jar with attribute called Permissions.

Sample MANIFEST.MF file
Manifest-Version: 1.0
Codebase: *
Permissions: all-permissions
Application-Library-Allowable-Codebase: *
Caller-Allowable-Codebase: *
Application-Name: Digital Certificate
Ant-Version: Apache Ant 1.8.3
Created-By: 1.6.0_25-b06 (Sun Microsystems Inc.)

Other Resources:
How to attach MANIFEST.MF file in jar in/using eclipse?
How to attach MANIFEST.MF file in jar in/using Netbeans?
For more details on MANIFEST attribute: