The IIS 8.5 web server must limit the amount of time a cookie persists.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-76727	IISW-SV-000135	SV-91423r2_rule		Medium

Description
ASP.NET provides a session state, which is available as the HttpSessionState class, as a method of storing session-specific information that is visible only within the session. ASP.NET session state identifies requests from the same browser during a limited time window as a session, and provides the ability to persist variable values for the duration of that session. Cookies associate session information with client information for the duration of a user’s connection to a website. Using cookies is a more efficient way to track session state than any of the methods that do not use cookies because cookies do not require any redirection.

Description

ASP.NET provides a session state, which is available as the HttpSessionState class, as a method of storing session-specific information that is visible only within the session. ASP.NET session state identifies requests from the same browser during a limited time window as a session, and provides the ability to persist variable values for the duration of that session. Cookies associate session information with client information for the duration of a user’s connection to a website. Using cookies is a more efficient way to track session state than any of the methods that do not use cookies because cookies do not require any redirection.

STIG	Date
IIS 8.5 Server Security Technical Implementation Guide	2018-01-03

Details

Check Text ( C-76383r2_chk )
Open the IIS 8.5 Manager. Click the IIS 8.5 web server name. Under the "ASP.NET" section, select "Session State". Under "Cookie Settings", verify the "Use Cookies" mode is selected from the "Mode:" drop-down list. Under Time-out (in minutes), verify “20 minutes or less” is selected. If the "Use Cookies” mode is selected and Time-out (in minutes) is configured for “20 minutes or less”, this is not a finding.

Check Text ( C-76383r2_chk )

Open the IIS 8.5 Manager.

Click the IIS 8.5 web server name.

Under the "ASP.NET" section, select "Session State".

Under "Cookie Settings", verify the "Use Cookies" mode is selected from the "Mode:" drop-down list.
Under Time-out (in minutes), verify “20 minutes or less” is selected.

If the "Use Cookies” mode is selected and Time-out (in minutes) is configured for “20 minutes or less”, this is not a finding.

Fix Text (F-83423r3_fix)
Open the IIS 8.5 Manager. Click the IIS 8.5 web server name. Under the "ASP.NET" section, select "Session State". Under "Cookie Settings", select the "Use Cookies" mode from the "Mode:" drop-down list. Under “Time-out (in minutes), enter a value of “20 or less”.