Safari browser on macOS shows security error after upgrading to macOS 10.15 and later.

Products

• ProxySG Software - SGOS
• ISG Proxy
• SG-VA

Issue/Introduction

Safari shows the error message "This connection is not private" after upgrade to macOS 10.15 and later. That works well if ProxySG is not SSL intercepted. 

Environment

Before 6.7.5.1.
7.x is not impacted.

Cause

The macOS 10.15 has been added some fields on their certificate and this is mandatory to certificate own apple site secure.  The description is here.
Requirements for trusted certificates in iOS 13 and macOS 10.15

So the most important value is "EKU" fields which is required and evaluated by Safari. Before 6.7.5.1 doesn't support this value. 

Resolution

This should be upgrade to 6.7.5.1 and later. EKU field has been added from 6.7.5.1.