I am about to upgrade the Security Essentials App (Installed on ES) to it's most current version 3.4.0. I read that Security Essentials depends on ES content update App. The question is do I need to update this to it's latest version as well? Thank u very much for your response in advance.
No, there is no dependency between Splunk Security Essentials (SSE) and Enterprise Security Content Updates (ESCU), but you should definitely update the ESCU frequently as it provides monthly updates to analytics, analytic stories, and associated content.
However, SSE does specify recommended add-ons within the app itself, stated as follows from the link below: "On the Security Content page, add-ons that you need to configure to make a detection work are now recommended and linked to from the detection. "
https://docs.splunk.com/Documentation/SSE/latest/ReleaseNotes/Enhancements