File Download Restriction must be enabled in all Office programs.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-223306	O365-CO-000024	SV-223306r508019_rule		Medium

Description
Disabling this setting allows websites to present file download prompts via code without the user specifically initiating the download. User preferences may also allow the download to occur without prompting or interaction with the user. Even if Internet Explorer prompts the user to accept the download, some websites abuse this functionality. Malicious websites may continually prompt users to download a file or present confusing dialog boxes to trick users into downloading or running a file. If the download occurs and it contains malicious code, the code could become active on user computers or the network.

Description

Disabling this setting allows websites to present file download prompts via code without the user specifically initiating the download. User preferences may also allow the download to occur without prompting or interaction with the user. Even if Internet Explorer prompts the user to accept the download, some websites abuse this functionality. Malicious websites may continually prompt users to download a file or present confusing dialog boxes to trick users into downloading or running a file. If the download occurs and it contains malicious code, the code could become active on user computers or the network.

STIG	Date
Microsoft Office 365 ProPlus Security Technical Implementation Guide	2020-09-11

Details

Check Text ( C-24979r442137_chk )
Verify the policy value for Computer Configuration >> Administrative Templates >> Microsoft Office 2016 (Machine) >> Security Settings >> IE Security >> Restrict File Download 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_filedownload If the value for all installed programs is REG_DWORD = 1, this is not a finding.

Check Text ( C-24979r442137_chk )

Verify the policy value for Computer Configuration >> Administrative Templates >> Microsoft Office 2016 (Machine) >> Security Settings >> IE Security >> Restrict File Download 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_filedownload

If the value for all installed programs is REG_DWORD = 1, this is not a finding.

Fix Text (F-24967r442138_fix)
Set the policy value for Computer Configuration >> Administrative Templates >> Microsoft Office 2016 (Machine) >> Security Settings >> IE Security >> Restrict File Download to "Enabled" and select the check boxes for all installed Office programs.