The IIS 10.0 web server must restrict inbound connections from non-secure zones.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-100159	IIST-SV-000142	SV-109263r1_rule		Medium

Description
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.

Description

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.

STIG	Date
Microsoft IIS 10.0 Server Security Technical Implementation Guide	2020-06-08

Details

Check Text ( C-99011r1_chk )
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.

Check Text ( C-99011r1_chk )

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 (F-105845r1_fix)
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.