ActiveX installation restriction must be enabled in all Office programs.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-223305	SRG-APP-000488	O365-CO-000023	SV-223305r961779_rule	2025-03-05	3

Description
Microsoft ActiveX controls allow unmanaged, unprotected code to run on the user computers. ActiveX controls do not run within a protected container in the browser like the other types of HTML or Microsoft Silverlight-based controls. Disabling or not configuring this setting does not block prompts for ActiveX control installations, and these prompts display to users. This could allow malicious code to become active on user computers or the network.

Description

Microsoft ActiveX controls allow unmanaged, unprotected code to run on the user computers. ActiveX controls do not run within a protected container in the browser like the other types of HTML or Microsoft Silverlight-based controls. Disabling or not configuring this setting does not block prompts for ActiveX control installations, and these prompts display to users. This could allow malicious code to become active on user computers or the network.

ℹ️ Check
Verify the policy value for Computer Configuration >> Administrative Templates >> Microsoft Office 2016 (Machine) >> Security Settings >> IE Security >> Restrict ActiveX Install is set to "Enabled" and the check box is selected for every installed Office program. Use the Windows Registry Editor to navigate to the following key: HKLM\software\microsoft\internet explorer\main\featurecontrol\feature_restrict_activexinstall If the value for all installed programs is REG_DWORD = 1, this is not a finding.

ℹ️ Check

Verify the policy value for Computer Configuration >> Administrative Templates >> Microsoft Office 2016 (Machine) >> Security Settings >> IE Security >> Restrict ActiveX Install is set to "Enabled" and the check box is selected for every installed Office program. Use the Windows Registry Editor to navigate to the following key: HKLM\software\microsoft\internet explorer\main\featurecontrol\feature_restrict_activexinstall If the value for all installed programs is REG_DWORD = 1, this is not a finding.

✔️ Fix
Set the policy value for Computer Configuration >> Administrative Templates >> Microsoft Office 2016 (Machine) >> Security Settings >> IE Security >> Restrict ActiveX Install to "Enabled" and select the check boxes for all installed Office programs.