Details

Setting limits on web requests helps to ensure availability of web services and may also help mitigate the risk of buffer overflow type attacks. The Maximum Query String Request Filter describes the upper limit on allowable query string lengths. Upon exceeding the configured value, IIS will generate a Status Code 404.15.

Solution

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

Open the IIS 10.0 Manager.

Click the site name under review.

Double-click the ‘Request Filtering’ icon.

Click ‘Edit Feature Settings’ in the ‘Actions’ pane.

Set the ‘Maximum Query String’ value to ‘2048’ or less.

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_IIS_10-0_Y20M10_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Windows.

References

• 800-53|SC-5(1)
• CAT|II
• CCI|CCI-001094
• Rule-ID|SV-218755r558649_rule
• STIG-ID|IIST-SI-000227
• STIG-Legacy|SV-109335
• STIG-Legacy|V-100231
• Vuln-ID|V-218755

Source

• Tenable.com/audits