The IIS 8.5 web server must restrict inbound connections from nonsecure zones.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-76741	IISW-SV-000142	SV-91437r2_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 nonsecure zones. Nonsecure zones are defined as any IP, subnet, or region that is defined as a threat to the organization. The nonsecure 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 nonsecure zones, through internal web server access list, 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 nonsecure zones. Nonsecure zones are defined as any IP, subnet, or region that is defined as a threat to the organization. The nonsecure 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 nonsecure zones, through internal web server access list, the web server can stop or slow denial of service (DoS) attacks on the web server.

STIG	Date
IIS 8.5 Server Security Technical Implementation Guide	2019-03-20

Details

Check Text ( C-76397r2_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 8.5 Manager. Click the IIS 8.5 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 be "Allow" are not restrictive enough to prevent connections from nonsecure zones, this is a finding.

Check Text ( C-76397r2_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 8.5 Manager.

Click the IIS 8.5 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 be "Allow" are not restrictive enough to prevent connections from nonsecure zones, this is a finding.

Fix Text (F-83437r1_fix)
Open the IIS 8.5 Manager. Click the IIS 8.5 web server name. Under "Management", double-click "Management Service". Stop the Web Management Service under the "Actions" pane. Configure only known, secure IP ranges are configured as "Allow". Select "Apply" in "Actions" pane. Restart the Web Management Service under the "Actions" pane.