Overview

An internal error appears while trying to define an application followed by a crash.

When creating a custom application using advanced options, the following internal error occurs, and the user interface displays log messages on the current page. This is followed by the Exinda being sluggish and crashing.

An internal error has occurred while loading this page. View the following log messages to assist in determining the cause.

Environment

Affected versions:

• ExOS 7.4.5
• ExOS 7.4.4 u2

Root Cause

This is caused by an uncaught exception generated by the creation of the invalid application. The application is invalid due to adding an asterisk character on the left side of a definition to denoted a wildcard. In the Exinda application definition, there is an implicit wildcard on the left side.

For example, to define hosts that don't have .info in the Top-Level Domains(TLDs) of a URL, it would be invalid to define it as: host !~ "*.info"

The correct definition should be: host !~ ".info" 

Resolution

Make sure to use a valid definition while configuring the L7 signatures. Exceptions due to the invalid application definition should not cause the system to crash. The device should be able to handle the error more gracefully, without crashing processes. This defect has been resolved and fixed in ExOS 7.4.8 release.