CIS Benchmark for Microsoft IIS 10: Web Server Hardening

What the official CIS Benchmark covers

CIS publishes the Microsoft IIS 10 Benchmark. Published recommendation areas include:

• Basic Configurations
• Configure Authentication and Authorization
• ASP.NET Configuration Recommendations
• Request Filtering and Other Restriction Modules
• IIS Logging Recommendations
• FTP Requests
• Transport Encryption

Recommendations are tagged by Level 1 and Level 2 profiles.

Key hardening areas

Mapped to real IIS 10 CIS families, without listing individual recommendation IDs:

Site and app-pool least privilege

Basic configuration themes that reduce unnecessary features and constrain application pool privileges.

Authentication & authorization

Secure authentication and authorization settings appropriate to the hosted applications.

Request filtering / attack surface

URL, query-string, extension, TRACE, ISAPI/CGI, and related restriction-module themes.

Logging & FTP hygiene

IIS log location and advanced logging themes, plus encrypted FTP and logon attempt restrictions where FTP is used.

TLS, ciphers & HSTS

Disable legacy SSL/TLS protocols, prefer strong cipher suites, and apply HSTS where appropriate.

Why manual CIS hardening is hard at scale

• Many sites on shared hosts create inconsistent request-filter exceptions.
• TLS settings regress after OS or cumulative updates.
• Logging locations and ETW settings drift between environments.
• One-off IIS Manager screenshots do not satisfy continuous evidence needs.

How CyberSilo’s CIS Benchmarking Tool helps

CyberSilo’s CIS Benchmarking Tool is built to turn “we have a PDF” into continuous configuration assessment:

• Map IIS hosts and sites into an assessable inventory against CIS Benchmark expectations for the platform.
• Score posture and surface gaps across auth, request filtering, logging, FTP, and transport themes.
• Detect configuration drift after patching or site deployments instead of waiting for the next audit scramble.
• Prioritise remediation work and keep exportable evidence for programmes that expect a hardened web baseline.

FAQ

Is there an official CIS Benchmark for IIS 10?

Yes. CIS publishes the Microsoft IIS 10 Benchmark with Level 1 and Level 2 recommendations.

What if we do not use ASP.NET?

Still review shared-host and request-filtering themes. Skip or exception ASP.NET-specific items with documentation where they do not apply.

Do we need every recommendation in the PDF?

Not always. Organisations commonly start with L1 request filtering and transport encryption, then expand.

How does CyberSilo relate to the official CIS PDF?

The official CIS Benchmark remains the authoritative recommendation source. CyberSilo automates assessment, scoring, drift detection, and remediation tracking.