5.1.18 Set 'Restrict File Download: outlook.exe' to 'Enabled:True'

Information

Prevents file downloads that are not initiated by the user. This Internet Explorer feature
control setting mitigates threats that can occur when an application programmatically uses
Internet Explorer functionality. The recommended state for this setting is- Enabled-True.

*Rationale*

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 interacting 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.

Solution

To implement the recommended configuration state, set the following Group Policy setting
to Enabled.Computer Configuration\Administrative Templates\Microsoft Office 2010
(Machine)\Security Settings\IE Security\Restrict File Download\Restrict File DownloadThen set the Restrict File Download- outlook.exe option to True.

Impact-User initiated downloads can still occur so the majority of legitimate user download
interactions remain unaffected. Hiding website-initiated prompt messages makes it
impossible for a malicious website to initiate a download by itself. Such a site can no longer
confuse a user into downloading a file that could then open on the user's computer to
execute an attack.However, some valid websites may initiate file downloads. If this setting is enabled, users
cannot view download prompts, and remain unaware when a download is available. If such
sites reside in an organization's intranet, they should display a link to prompt users to
initiate valid downloads if the automatic download process does not occur. This type of
functionality is already in common use on many major internet sites and should not
confuse users.
It is possible that some advanced users may expect their user preferences to control this
behavior, and for this reason, they may be confused when this preference is overridden by
this setting.

See Also

https://workbench.cisecurity.org/files/530

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CSCv6|3.1

Plugin: Windows

Control ID: 4f6a5111c0951b38c9a4f5521be886231a79bc605aa1a7cca2a716b4a5ca57fd