The Windows Server 2025 "Modify firmware environment values" user right must only be assigned to the Administrators group.

Inappropriately granting user rights provides system, administrative, and other high-level capabilities. Accounts with the "Modify firmware environment values" user right can change hardware configuration environment variables. This could result in hardware failures or a denial of service.

Verify the effective setting in Local Group Policy Editor. Run gpedit.msc. Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment. If any accounts or groups other than the following are granted the "Modify firmware environment values" user right, this is a finding: - Administrators. For server core installations, run the following command: Secedit /Export /Areas User_Rights /cfg c:\path\filename.txt Review the text file. If any SIDs other than the following are granted the "SeSystemEnvironmentPrivilege" user right, this is a finding: S-1-5-32-544 (Administrators)

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> User Rights Assignment >> Modify firmware environment values to include only the following accounts or groups: - Administrators.