Check: O365-EX-000004
Microsoft Office 365 ProPlus STIG:
O365-EX-000004
(in versions v2 r11 through v1 r2)
Title
Dynamic Data Exchange (DDE) server lookup in Excel must be blocked. (Cat II impact)
Discussion
This policy setting allows you to control whether Dynamic Data Exchange (DDE) server lookup is allowed. By default, DDE server lookup is turned on, but users can turn off DDE server lookup by going to File >> Options >> Trust Center >> Trust Center Settings >> External Content. If you enable this policy setting, DDE server lookup is not allowed, and users cannot turn on DDE server lookup in the Trust Center. Note: If you are using Dynamic Data Exchange (DDE) server launch, which is not recommended, do not enable this policy setting, because DDE server launch requires DDE server lookup to be on. If you disable or do not configure this policy setting, DDE server lookup is turned on, but users can turn off DDE server lookup in the Trust Center. Note: This policy setting only applies to subscription versions of Office, such as Office 365 ProPlus.
Check Content
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Excel 2016 >> Excel Options >> Security >> Trust Center >> External Content >> Don't allow Dynamic Data Exchange (DDE) server lookup in Excel is set to "Enabled". Use the Windows Registry Editor to navigate to the following key: HKCU\software\policies\microsoft\office\16.0\excel\security\external content If the value for "disableddeserverlookup" is REG_DWORD = 1, this is not a finding.
Fix Text
Set policy value for User Configuration >> Administrative Templates >> Microsoft Excel 2016 >> Excel Options >> Security >> Trust Center >> External Content >> Don't allow Dynamic Data Exchange (DDE) server lookup in Excel to "Enabled".
Additional Identifiers
Rule ID: SV-223313r879628_rule
Vulnerability ID: V-223313
Group Title: SRG-APP-000207
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-001662 |
The information system takes organization-defined corrective action when organization-defined unacceptable mobile code is identified. |
Controls
Number | Title |
---|---|
SC-18 (1) |
Identify Unacceptable Code / Take Corrective Actions |