Open/Save actions for Excel 3 macrosheets and add-in files must be blocked.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-26599	DTOO115	SV-53626r1_rule	ECSC-1	Medium

Description
This setting specifies whether users can open, view, edit, or save files saved in the specified format. Enabling block of the specified format mitigates zero-day security attacks (which are attacks that occur between the time that a vulnerability becomes publicly known and a software update or service pack is available) by temporarily preventing users from opening specific types of files and to prevent a user from opening files that have been saved in earlier and pre-release (beta) Microsoft Office formats.

Description

This setting specifies whether users can open, view, edit, or save files saved in the specified format. Enabling block of the specified format mitigates zero-day security attacks (which are attacks that occur between the time that a vulnerability becomes publicly known and a software update or service pack is available) by temporarily preventing users from opening specific types of files and to prevent a user from opening files that have been saved in earlier and pre-release (beta) Microsoft Office formats.

STIG	Date
Microsoft Excel 2013 STIG	2014-04-03

Details

Check Text ( C-47755r1_chk )
Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2013 -> Excel Options -> Security -> Trust Center -> File Block Settings "Excel 3 macrosheets and add-in files" is set to "Enabled: Open/Save blocked, use open policy". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\15.0\excel\security\fileblock Criteria: If the value XL3Macros is REG_DWORD = 2, this is not a finding.

Check Text ( C-47755r1_chk )

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2013 -> Excel Options -> Security -> Trust Center -> File Block Settings "Excel 3 macrosheets and add-in files" is set to "Enabled: Open/Save blocked, use open policy".

Procedure: Use the Windows Registry Editor to navigate to the following key:

HKCU\Software\Policies\Microsoft\Office\15.0\excel\security\fileblock

Criteria: If the value XL3Macros is REG_DWORD = 2, this is not a finding.

Fix Text (F-46551r1_fix)
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2013 -> Excel Options -> Security -> Trust Center -> File Block Settings "Excel 3 macrosheets and add-in files" to "Enabled: Open/Save blocked, use open policy".