Check: O365-EX-000002
Microsoft Office 365 ProPlus STIG:
O365-EX-000002
(in version v2 r11)
Title
VBA Macros not digitally signed must be blocked in Excel. (Cat II impact)
Discussion
This policy setting controls how the specified applications warn users when Visual Basic for Applications (VBA) macros are present. If you enable this policy setting, you can choose from four options for determining how the specified applications will warn the user about macros: - Disable all with notification: The application displays the Trust Bar for all macros, whether signed or unsigned. This option enforces the default configuration in Office. This option also allows users to potentially enable unsigned/untrusted macros. If a site requires the use of macros, they must be signed /approved and added to appropriate locations listed in the Trust Center Settings. - Disable all except digitally signed macros: The application displays the Trust Bar for digitally signed macros, allowing users to enable them or leave them disabled. Any unsigned macros are disabled, and users are not notified. - Disable all without notification: The application disables all macros, whether signed or unsigned, and does not notify users. - Enable all macros (not recommended): All macros are enabled, whether signed or unsigned. This option can significantly reduce security by allowing dangerous code to run undetected.
Check Content
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Excel 2016 >> Excel Options >> Security >> Trust Center >> "Macro Notification Settings" is set to "Enabled" and "Disable VBA macros except digitally signed macros" from the Options is selected. Use the Windows Registry Editor to navigate to the following key: HKCU\software\policies\Microsoft\office\16.0\excel\security If the value vbawarnings is REG_DWORD = 3, this is not a finding. A value of REG_DWORD = 4 is also acceptable. If the registry key does not exist or is not configured properly, this is a finding.
Fix Text
Set the policy value for User Configuration >> Administrative Templates >> Microsoft Excel 2016 >> Excel Options >> Security >> Trust Center >> "Macro Notification Settings" is set to "Enabled" and select "Disable VBA macros except digitally signed macros" from the Options.
Additional Identifiers
Rule ID: SV-223311r928375_rule
Vulnerability ID: V-223311
Group Title: SRG-APP-000141
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000381 |
The organization configures the information system to provide only essential capabilities. |
Controls
Number | Title |
---|---|
CM-7 |
Least Functionality |