Title

Internet Explorer Processes for MK protocol must be enforced (IExplore). (Cat II impact)

Discussion

The MK Protocol Security Restriction policy setting reduces attack surface area by blocking the seldom used MK protocol. Some older web applications use the MK protocol to retrieve information from compressed files. Because the MK Protocol is not widely used, it should be blocked wherever it is not needed. Setting this policy to enabled, blocks the MK protocol for Windows Explorer and Internet Explorer, which causes resources that use the MK protocol to fail. Disabling this setting allows applications to use the MK protocol API. Because the MK protocol is not widely used, it should be blocked wherever it is not needed. This guide recommends you configure this setting to Enabled to block the MK protocol unless specifically needed it in the environment. Note: Because resources that use the MK protocol will fail when deploying this setting, ensure none of the applications use the MK protocol.

Check Content

The policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Security Features -> MK Protocol Security Restriction -> "Internet Explorer Processes" must be “Enabled”. Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_DISABLE_MK_PROTOCOL Criteria: If the value iexplore.exe is REG_SZ = 1, this is not a finding.

Fix Text

Set the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Security Features -> MK Protocol Security Restriction -> "Internet Explorer Processes" to “Enabled”.

Additional Identifiers

Rule ID: SV-40667r1_rule

Vulnerability ID: V-15551

Group Title: DTBI605 - MK Protocol - IExplore

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.