Protected Mode must be enforced (Restricted Sites zone).

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-46685	DTBI490-IE11	SV-59549r1_rule	ECSC-1	Medium

Description
Protected Mode protects Internet Explorer from exploited vulnerabilities by reducing the locations Internet Explorer can write to in the registry and the file system. If you enable this policy setting, Protected Mode will be turned on. Users will not be able to turn off Protected Mode. If you disable this policy setting, Protected Mode will be turned off. It will revert to Internet Explorer 6 behavior that allows for Internet Explorer to write to the registry and the file system. Users will not be able to turn on Protected Mode. If you do not configure this policy, users will be able to turn on or off Protected Mode.

Description

Protected Mode protects Internet Explorer from exploited vulnerabilities by reducing the locations Internet Explorer can write to in the registry and the file system. If you enable this policy setting, Protected Mode will be turned on. Users will not be able to turn off Protected Mode. If you disable this policy setting, Protected Mode will be turned off. It will revert to Internet Explorer 6 behavior that allows for Internet Explorer to write to the registry and the file system. Users will not be able to turn on Protected Mode. If you do not configure this policy, users will be able to turn on or off Protected Mode.

STIG	Date
Microsoft Internet Explorer 11 Security Technical Implementation Guide	2017-12-12

Details

Check Text ( C-49837r2_chk )
The policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Internet Control Panel -> Security Page -> Restricted Sites Zone -> 'Turn on Protected Mode' must be 'Enabled', and 'Enable' selected from the drop-down box. Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4 Criteria: If the value "2500" is REG_DWORD = 0, this is not a finding.

Check Text ( C-49837r2_chk )

The policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Internet Control Panel -> Security Page -> Restricted Sites Zone -> 'Turn on Protected Mode' must be 'Enabled', and 'Enable' selected from the drop-down box. Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4 Criteria: If the value "2500" is REG_DWORD = 0, this is not a finding.

Fix Text (F-50449r1_fix)
Set the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Internet Control Panel -> Security Page -> Restricted Sites Zone -> 'Turn on Protected Mode' to 'Enabled' and select 'Enable', from the drop-down box.