STIGUI
V-223300CAT II — Medium severitySV-223300r961863_rule

The Local Machine Zone Lockdown Security must be enabled in all Office programs.

Rule version O365-CO-000018 · STIG v3 · 2026-02-12

Discussion

Internet Explorer places restrictions on each web page users can use the browser to open. Web pages on a user's local computer have the fewest security restrictions and reside in the Local Machine zone, making this security zone a prime target for malicious users and code. Disabling or not configuring this setting could allow pages in the Internet zone to navigate to pages in the Local Machine zone to then run code to elevate privileges. This could allow malicious code or users to become active on user computers or the network.

Check

Verify the policy value for Computer Configuration >> Administrative Templates >> Microsoft Office 2016 (Machine) >> Security Settings >> IE Security >> Local Machine Zone Lockdown Security 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_localmachine_lockdown

If the value for all installed Office 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 >> Local Machine Zone Lockdown to "Enabled" and select the check boxes for all installed Office programs.

Identifiers

Group ID
V-223300
Group title
SRG-APP-000516
Rule ID
SV-223300r961863_rule
Check ID
C-24973r442119_chk
Fix ID
F-24961r442120_fix