1.21.1 (L1) Ensure 'Specifies whether to allow websites to make requests to more-private network endpoints' is set to 'Disabled'

Information

This policy setting controls whether insecure websites are allowed to make requests to more private network endpoints.

A network endpoint is more private than another if:

- Its IP address is localhost and the other is not.
- Its IP address is private and the other is public.

In the future, depending on spec evolution, this policy might apply to all cross-origin requests directed at private IPs or localhost.

A website is deemed secure if it meets the definition of a secure context in

https://developer.mozilla.org/en-US/docs/Web/Security/Secure_Contexts

. Otherwise, it will be treated as an insecure context.

The recommended state for this setting is: Disabled

Note: This policy relates to the Private Network Access specification. See

https://wicg.github.io/private-network-access/

for more details.

Note #2: If this policy is not configured or set to

Disabled

, the default behavior for requests from insecure contexts to more-private network endpoints will depend on the user's personal configuration for the

BlockInsecurePrivateNetworkRequests

feature, which may be set by a field trial or on the command line.

Allowing public internet sites to 'peek' behind your firewall by using the user's browser to mix intranet resources into internet-delivered pages represents a dangerous attack surface. The baseline requires enforcement of the new browser restriction that any such intranet requests are blocked if the internet page was delivered over insecure HTTP.

Note: If for some reason you need to permit insecure cross-network requests for legacy sites, you can configure temporary exceptions in

Allow the listed sites to make requests to more-private network endpoints from insecure contexts

.

Solution

To establish the recommended configuration via GP, set the following UI path to Disabled :

Computer Configuration\Policies\Administrative Templates\Microsoft Edge\Private Network Request Settings\Specifies whether to allow websites to make requests to more-private network endpoints

Note: This Group Policy path may not exist by default. It is provided by the Group Policy template MSEdge.admx/adml that can be downloaded from:

Download Microsoft Edge for Business - Microsoft

.

Impact:

Users will be unable to allow non-secure public contexts to request resources from private addresses.

See Also

https://workbench.cisecurity.org/benchmarks/18501

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b.

Plugin: Windows

Control ID: fa1aa5ea90a59e662538a884867ecf9abbff4193bb6925874237515fa27172c6