Detections
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18.9.4.1 Ensure 'Encryption Oracle Remediation' is set to 'Enabled: Force Updated Clients'

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This audit has been deprecated and will be removed in a future update.

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Information

Some versions of the CredSSP protocol that is used by some applications (such as Remote Desktop Connection) are vulnerable to an encryption oracle attack against the client. This policy controls compatibility with vulnerable clients and servers and allows you to set the level of protection desired for the encryption oracle vulnerability.

The recommended state for this setting is: Enabled: Force Updated Clients.

Rationale:

This setting is important to mitigate the CredSSP encryption oracle vulnerability, for which information was published by Microsoft on 03/13/2018 in CVE-2018-0886 | CredSSP Remote Code Execution Vulnerability. All versions of Windows from Windows Vista onwards are affected by this vulnerability, and will be compatible with this recommendation provided that they have been patched at least through May 2018 (or later).

Impact:

Client applications which use CredSSP will not be able to fall back to the insecure versions and services using CredSSP will not accept unpatched clients. This setting should not be deployed until all remote hosts support the newest version, which is achieved by ensuring that all Microsoft security updates at least through May 2018 are installed.

Solution

To establish the recommended configuration, set the following Device Configuration Policy to Enabled: Force Updated Clients:

To access the Device Configuration Policy from the Intune Home page:

Click Devices

Click Configuration profiles

Click Create profile

Select the platform (Windows 10 and later)

Select the profile (Administrative Templates)

Click Create

Enter a Name

Click Next

Configure the following Setting

Path: Computer Configuration\System\Credentials Delegation
Setting Name: Encryption Oracle Remediation
Configuration: Enabled: Force Updated Clients

Select OK

Continue through the Wizard to complete the creation of the profile (profile assignments, applicability etc.)

Note: More than one configuration setting from each of the Configuration profiles (ex: Administrative Templates, Custom etc.) can be added to each Device Configuration Policy.

Default Value:

Without the May 2018 security update: Enabled: Vulnerable (Client applications which use CredSSP will expose the remote servers to attacks by supporting fall back to the insecure versions and services using CredSSP will accept unpatched clients.)

With the May 2018 security update: Enabled: Mitigated (Client applications which use CredSSP will not be able to fall back to the insecure version but services using CredSSP will accept unpatched clients.)

See Also

https://workbench.cisecurity.org/benchmarks/14355

Item Details

References: CSCv7|3.4

Plugin: Windows

Control ID: 9d8882f728e4dae3218fa1a6b34aadc8d0ef968877765211040b89abaf44c565