Mappings to unused and vulnerable scripts on the IIS 8.5 website must be removed.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-214455	IISW-SI-000215	SV-214455r695296_rule		Medium

Description
IIS 8.5 will either allow or deny script execution based on file extension. The ability to control script execution is controlled through two features with IIS 8.5, “Request Filtering” and "Handler Mappings". For "Request Filtering", the ISSO must document and approve all allowable file extensions the website allows (white list) and denies (black list) by the website. The white list and black list will be compared to the "Request Filtering" in IIS 8. "Request Filtering" at the site level take precedence over "Request Filtering" at the server level.

Description

IIS 8.5 will either allow or deny script execution based on file extension. The ability to control script execution is controlled through two features with IIS 8.5, “Request Filtering” and "Handler Mappings". For "Request Filtering", the ISSO must document and approve all allowable file extensions the website allows (white list) and denies (black list) by the website. The white list and black list will be compared to the "Request Filtering" in IIS 8. "Request Filtering" at the site level take precedence over "Request Filtering" at the server level.

STIG	Date
Microsoft IIS 8.5 Site Security Technical Implementation Guide	2021-12-28

Details

Check Text ( C-15664r695294_chk )
For Request Filtering, the ISSO must document and approve all allowable scripts the website allows (white list) and denies (black list). The white list and black list will be compared to the Request Filtering in IIS 8.5. Open the IIS 8.5 Manager. Click the site name under review. Double-click "Request Filtering". If any script file extensions from the black list are enabled, this is a finding.

Check Text ( C-15664r695294_chk )

For Request Filtering, the ISSO must document and approve all allowable scripts the website allows (white list) and denies (black list). The white list and black list will be compared to the Request Filtering in IIS 8.5.

Open the IIS 8.5 Manager.

Click the site name under review.

Double-click "Request Filtering".

If any script file extensions from the black list are enabled, this is a finding.

Fix Text (F-15662r695295_fix)
Open the IIS 8.5 Manager. Click the site name under review. Double-click "Request Filtering". Deny any script file extensions listed on the black list. Select "Apply" from the "Actions" pane.