STIGQter: STIG Summary: Microsoft IIS 10.0 Site Security Technical Implementation Guide Version: 2 Release: 16 Benchmark Date: 01 Jul 2026:

The IIS 10.0 private website must employ cryptographic mechanisms (TLS) and require client certificates.

DISA Rule

SV-218768r1156529_rule

Vulnerability Number

V-218768

Group Title

SRG-APP-000429-WSR-000113

Rule Version

IIST-SI-000242

Severity

CAT I

CCI(s)

• CCI-002476 - Implement cryptographic mechanisms to prevent unauthorized disclosure of organization-defined information at rest on organization-defined system components.

Weight

10

Fix Recommendation

Follow the procedures below for each site hosted on the IIS 10.0 web server:

Open the IIS 10.0 Manager.

Double-click the "SSL Settings" icon under the "IIS" section.

Select the "Require SSL" setting.

Select the "Client Certificates Required" setting.

Click "Apply" in the "Actions" pane.

Click the site under review.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate "system.webServer/security/access".

Click on the drop-down list for "sslFlags".

Select the "Ssl128" check box.

Click "Apply" in the "Actions" pane.

Check Contents

Notes:
- If SSL is installed on load balancer/proxy server through which traffic is routed to the IIS 10.0 server, and the IIS 10.0 server receives traffic from the load balancer/proxy server, the SSL requirement must be met on the load balancer/proxy server. In this case, this requirement is not applicable.
- If this is a public-facing web server, this requirement is not applicable.
- If this server is hosting WSUS, this requirement is not applicable.
- If the server being reviewed is hosting SharePoint, this is not applicable.
- If the server being reviewed is hosting Simple Certificate Enrollment Services (SCEP), this is not applicable.
- If the server being reviewed is hosting Network Device Enrollment Services (NDES), this is not applicable.
- If the server is providing OCSP, and not otherwise hosting any content, this requirement is not applicable.
- If the server is providing CRL, and not otherwise hosting any content, this requirement is not applicable.

Follow the procedures below for each site hosted on the IIS 10.0 web server:

Open the IIS 10.0 Manager.

Double-click the "SSL Settings" icon under the "IIS" section.

Verify "Require SSL" is checked.

Verify "Client Certificates Required" is selected.

Click the site under review.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate "system.webServer/security/access".

The value for "sslFlags" set must include "ssl128".

If the "Require SSL" is not selected, this is a finding.

If the "Client Certificates Required" is not selected, this is a finding. Note: "Client Certificates Required" can be considered Not Applicable in a Single Sign On (SSO) scenario where client certificates are no longer processed locally.

If the "sslFlags" is not set to "ssl128", this is a finding.

Vulnerability Number

V-218768

Documentable

False

Rule Version

IIST-SI-000242

Severity Override Guidance

Notes:
- If SSL is installed on load balancer/proxy server through which traffic is routed to the IIS 10.0 server, and the IIS 10.0 server receives traffic from the load balancer/proxy server, the SSL requirement must be met on the load balancer/proxy server. In this case, this requirement is not applicable.
- If this is a public-facing web server, this requirement is not applicable.
- If this server is hosting WSUS, this requirement is not applicable.
- If the server being reviewed is hosting SharePoint, this is not applicable.
- If the server being reviewed is hosting Simple Certificate Enrollment Services (SCEP), this is not applicable.
- If the server being reviewed is hosting Network Device Enrollment Services (NDES), this is not applicable.
- If the server is providing OCSP, and not otherwise hosting any content, this requirement is not applicable.
- If the server is providing CRL, and not otherwise hosting any content, this requirement is not applicable.

Follow the procedures below for each site hosted on the IIS 10.0 web server:

Open the IIS 10.0 Manager.

Double-click the "SSL Settings" icon under the "IIS" section.

Verify "Require SSL" is checked.

Verify "Client Certificates Required" is selected.

Click the site under review.

Select "Configuration Editor" under the "Management" section.

From the "Section:" drop-down list at the top of the configuration editor, locate "system.webServer/security/access".

The value for "sslFlags" set must include "ssl128".

If the "Require SSL" is not selected, this is a finding.

If the "Client Certificates Required" is not selected, this is a finding. Note: "Client Certificates Required" can be considered Not Applicable in a Single Sign On (SSO) scenario where client certificates are no longer processed locally.

If the "sslFlags" is not set to "ssl128", this is a finding.

Check Content Reference

M

Target Key

4051