Title

The IIS 10.0 web server must restrict inbound connections from non-secure zones. (Cat II impact)

Discussion

Remote access to the web server is any access that communicates through an external, non-organization-controlled network. Remote access can be used to access hosted applications or to perform management functions. A web server can be accessed remotely and must be capable of restricting access from what the DoD defines as non-secure zones. Non-secure zones are defined as any IP, subnet, or region defined as a threat to the organization. The non-secure zones must be defined for public web servers logically located in a DMZ, as well as private web servers with perimeter protection devices. By restricting access from non-secure zones through internal web server access lists, the web server can stop or slow denial of service (DoS) attacks on the web server.

Check Content

Note: This requirement applies to the Web Management Service. If the Web Management Service is not installed, this is Not Applicable. Open the IIS 10.0 Manager. Click the IIS 10.0 web server name. Under "Management", double-click "Management Service". If "Enable remote connections" is not selected, this is Not Applicable. If "Enable remote connections" is selected, review the entries under "IP Address Restrictions". Verify only known, secure IP ranges are configured as "Allow". If "IP Address Restrictions" are not configured or IP ranges configured to "Allow" are not restrictive enough to prevent connections from nonsecure zones, this is a finding.

Fix Text

Open the IIS 10.0 Manager. Click the IIS 10.0 web server name. Under "Management", double-click "Management Service". Stop the Web Management Service under the "Actions" pane. Configure only known, secure IP ranges as "Allow". Select "Apply" in "Actions" pane. Restart the Web Management Service under the "Actions" pane.

Additional Identifiers

Rule ID: SV-218812r879692_rule

Vulnerability ID: V-218812

Group Title: SRG-APP-000315-WSR-000004

Expert Comments

CCIs tied to check.

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