i want step by step process regarding SecureBoot2023(Prechecks, installation, post checks) to deploy from SCCM/MECM

Below is a step-by-step outline aligned to the phases described, using the Secure Boot 2023 guidance and registry-/event-based signals that can be automated from SCCM/MECM or Intune. Only actions that are explicitly documented in the context are included.

Phase 1 – Detect devices with Windows UEFI CA 2023

Goal: Build an inventory of which devices already have the Windows UEFI CA 2023 certificate and which are also booting from the 2023 boot manager.

1. Pre-check: Secure Boot state
   • Use PowerShell on each device (via SCCM/Intune script or baseline):
     • Confirm-SecureBootUEFI (or read HKLM:\SYSTEM\CurrentControlSet\Control\SecureBoot) to determine whether Secure Boot is enabled.
   • This is the same signal used in the Secure Boot certificate guidance.
2. Detect 2023 certificate and boot manager status
   • Use the documented registry key from the Enterprise Deployment Guidance for CVE‑2023‑24932:
     • Path: HKLM\SYSTEM\CurrentControlSet\Control\SecureBoot\Servicing
     • Value: WindowsUEFICA2023Capable (REG_DWORD)
     • Meaning:
       • 0 or missing: Windows UEFI CA 2023 certificate is not in the DB.
       • 1: Windows UEFI CA 2023 certificate is in the DB.
       • 2: Windows UEFI CA 2023 certificate is in the DB and the system is starting from the 2023 signed boot manager.
   • Deploy a PowerShell script from SCCM/MECM or Intune to read this value and report it back (e.g., as discovery data, compliance setting, or custom inventory).
3. Optional: Use UEFICA2023Status
   • The Secure Boot certificate guidance and WinCS documentation also reference:
     • HKLM:\SYSTEM\CurrentControlSet\Control\SecureBoot\Servicing → UEFICA2023Status.
   • If UEFICA2023Status shows “Updated”, the certificates are already updated and no further WinCS actions are required.
4. Optional: Event-based validation
   • For more complete auditing of certificate updates, use the event IDs referenced in the Secure Boot configuration guidance:
     • Event ID 1801 and 1808, as documented in “Secure Boot DB and DBX variable update events”.
   • These events can be collected centrally (e.g., via event log forwarding) to validate that certificate updates have been applied.

Phase 2 – Deploy CA 2023 to all UEFI devices

Goal: Ensure all UEFI devices (regardless of Secure Boot ON/OFF) receive the Windows UEFI CA 2023 certificate and the updated boot manager.

The documented mitigations for CVE‑2023‑24932 are:

1. Mitigation 1 – Install updated certificate definitions to DB
   • Adds the Windows UEFI CA 2023 certificate to the UEFI Secure Boot DB so firmware trusts boot applications signed by this certificate.
2. Mitigation 2 – Update the boot manager
   • Applies the Windows boot manager signed with the Windows UEFI CA 2023 certificate.

Deployment mechanics (what Windows does once targeted):

• When a device is targeted for Secure Boot certificate updates, Windows sets bits in the AvailableUpdates registry value under HKLM\SYSTEM\CurrentControlSet\Control\SecureBoot.
• A scheduled task runs every 12 hours and processes these bits in order:
  1. Add Windows UEFI CA 2023 to DB (bit 0x0040).
  2. Apply Microsoft Option ROM UEFI CA 2023 and Microsoft UEFI CA 2023 to DB, with conditional behavior controlled by bit 0x4000.
  3. Add Microsoft Corporation KEK 2K CA 2023 (bit 0x0004).
  4. Apply the boot manager signed by Windows UEFI CA 2023 (bit 0x0100) to the boot partition.
• Each step must complete successfully before the next step runs.

From SCCM/MECM or Intune, the practical steps are:

1. Ensure the OS updates that carry Mitigation 1 and Mitigation 2 are deployed
   • Deploy the cumulative updates that contain the Secure Boot certificate updates and the 2023 boot manager to all UEFI devices.
2. (If using WinCS) Configure Secure Boot updates
   • The WinCS CLI and configuration key can be used to set the update configuration so the scheduled Secure Boot task performs the certificate and boot manager updates on the next run.
   • After setting the configuration, the scheduled task Secure-Boot-Update runs and applies the certificates and boot manager as described.
3. Reboot behavior
   • The boot manager update is staged and applied on reboot.
   • Windows will detect that a restart is needed; the update is applied when the device naturally restarts (e.g., during monthly updates).

This supports the “bottom line” state:

• UEFI + Secure Boot OFF + CA 2023 deployed = device is ready; once Secure Boot is enabled, the 2023 chain is already in place.

Phase 3 – Audit devices with Secure Boot OFF

1. Use the same PowerShell/registry checks as in Phase 1
   • Confirm-SecureBootUEFI or HKLM\SYSTEM\CurrentControlSet\Control\SecureBoot to determine Secure Boot state.
2. Combine with CA 2023 status
   • Correlate:
     • SecureBootEnabled (true/false or registry equivalent).
     • WindowsUEFICA2023Capable (0/1/2).
   • This allows identification of:
     • Devices with Secure Boot OFF but WindowsUEFICA2023Capable = 1 or 2 (safe to enable Secure Boot later).
     • Devices with Secure Boot OFF and WindowsUEFICA2023Capable = 0 or missing (need Phase 2 deployment first).
3. Inventory and sampling
   • The Secure Boot certificate guidance recommends collecting:
     • HostName, CollectionTime.
     • SecureBootEnabled, HighConfidenceOptOut, AvailableUpdates.
     • Servicing key values such as UEFICA2023Status.
   • This can be implemented as SCCM hardware inventory extensions or Intune reporting.

Phase 4 – BIOS/UEFI change to enable Secure Boot

The context does not prescribe a specific remote method to toggle firmware settings. However, the strategy is:

1. Only enable Secure Boot on devices where:
   • WindowsUEFICA2023Capable is 1 or 2 (certificate present), and
   • The device has successfully applied the Secure Boot certificate updates (e.g., UEFICA2023Status = “Updated” or events 1801/1808 show success).
2. Coordinate with OEM guidance
   • The Secure Boot certificate guidance notes that some devices may require OEM BIOS updates or have known limitations; these are reflected in the “confidence” classifications (High Confidence, Under Observation, Temporarily Paused, Not Supported, etc.).
   • For devices in “Temporarily Paused” or “Not Supported” categories, follow OEM and Microsoft guidance before enabling Secure Boot.

Phase 5 – Verify smooth transition for devices holding CA 2023

1. Post-check: Confirm 2023 certificate and boot manager
   • Re-run the Phase 1 detection:
     • WindowsUEFICA2023Capable should be 2 (certificate in DB and system starting from 2023 boot manager).
     • UEFICA2023Status should show “Updated” if using that value.
2. Post-check: Secure Boot enabled
   • Confirm Secure Boot is now ON via Confirm-SecureBootUEFI or the SecureBoot registry key.
3. Event log validation
   • Review event IDs 1801 and 1808 to confirm the Secure Boot DB and boot manager updates completed successfully.
4. Ongoing monitoring
   • Continue to monitor the WindowsUEFICA2023Capable and UEFICA2023Status values and Secure Boot state across the fleet.
   • Use the “Secure Boot Confidence Levels” guidance to decide whether to proceed broadly or pause for specific device classes.

Key long-term requirement

• The Enterprise Deployment Guidance for CVE‑2023‑24932 emphasizes that the Microsoft Windows Production PCA 2011 certificate in firmware expires in October 2026.
• Devices must have the Windows UEFI CA 2023 certificate in firmware and be able to start from the 2023-signed boot manager before that date, or they will no longer be able to receive Windows updates.

References:

• Secure Boot Certificate updates: Guidance for IT professionals and organizations
• Enterprise Deployment Guidance for CVE-2023-24932
• Windows Configuration System (WinCS) APIs for Secure Boot
• Windows Secure Boot certificate expiration and CA updates
• Secure Boot certificates have been updated but are not yet applied - Microsoft Q&A