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May 25, 2026
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PFE Architecture Question: FortiClient Custom Installer Distribution – Dedicated DMZ File Server vs. Exposing LAN EMS Apache via WAF

  • May 25, 2026
  • 2 replies
  • 58 views

Hey everyone,

​I'm currently working on my PFE (Graduation Project) focused on deploying a Zero Trust Architecture using the Fortinet Security Fabric. I’m finalizing the deployment strategy for the FortiClient custom installer distribution, and I'd love to get some architectural feedback from the community.

​The Goal: Securely distribute the custom installer generated in EMS to remote endpoints during an initial onboarding period, and then tightly lock down registration afterward.

​The Environment: My core EMS server lives inside the secure Server LAN.

​For both options below, the download page is protected by a FortiWeb WAF that requires Active Directory (AD) pre-authentication before a user can access the installer. However, given the recent high-severity vulnerabilities (like the 8013 auth bypass CVEs), I am highly paranoid about zero-days and expanding the internal attack surface unnecessarily.

​Here are the two design paths I am debating:

​Option 1 (Dedicated DMZ Server + WAF + AD Auth): I spin up a separate, dedicated web server inside the DMZ (alongside our public website) purely to host and serve the static custom .msi/.pkg installer files. The WAF handles AD auth and protects this DMZ server. The internal EMS server remains completely hidden from the internet.

​Option 2 (Exposing LAN EMS Apache + WAF + AD Auth): I don't build a new DMZ server. Instead, the WAF handles AD auth and forwards successful traffic straight into the internal Server LAN to expose the built-in Apache web service running directly on the EMS server to download the custom installer page.

​My Proposed Security Lifecycle:

​To mitigate the risk of leaving registration open, my post-onboarding plan is:

​During Onboarding: Allow public access (via AD credential login on FortiWeb) to download the pre-configured custom installer (which has the telemetry key embedded).

​Post-Onboarding: Disable the global invite code and change the telemetry key on EMS. This effectively makes that initial custom installer useless for any unapproved devices trying to phone home.

​Ongoing Operations: For any new client onboarding after this main phase, I will generate an individual, strictly monitored invite code to track exactly how many times it's used and tightly control registered devices.

​My Questions for you guys:

​Is Option 1 still the superior choice here from a security standpoint? My logic is that even with FortiWeb doing AD pre-authentication, if a zero-day drops that allows a WAF/Auth bypass, Option 1 only compromises a dummy file server in the DMZ. With Option 2, a bypass gives an attacker direct access to the EMS server's built-in Apache service right inside the Server LAN.

​Does my logic for rotating the telemetry key and switching to individual invite codes hold up in a real production environment?   Thanks in advance for any insights!

2 replies

vpolovnikov
Staff & Editor
Staff & Editor
May 25, 2026

This solution makes FortiClient upgrades via EMS deployment feature impossible. When new version of FortiClient gets released, you’ll probably want to upgrade your fleet without much user intervention and in automated rather effortless fashion. However, having AD authentication enforced on the download URL will break deployment of a new version which may lead to security issues in case of vulnerability in older FortiClient version(s).

As for the onboarding process, I’d say it doesn’t matter where the installer is retrieved from (given it was created on EMS and points to it). What matters is consecutive registration which requires connectivity to EMS over Telemetry port. As for invite codes, you don’t have to necessarily delete it; setting an expiration date will work too. 

AEK
SuperUser
SuperUser
May 25, 2026

Option 3: Use ZTNA tags instead of AD authentication.

Also note that EMS should be in DMZ if you need telemetry for your remote clients.

AEK
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