IIS 10.0 website session IDs must be sent to the client using TLS.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-218769	SRG-APP-000439-WSR-000152	IIST-SI-000244	SV-218769r961632_rule	2025-02-11	2

Description
The HTTP protocol is a stateless protocol. To maintain a session, a session identifier is used. The session identifier is a piece of data used to identify a session and a user. If the session identifier is compromised by an attacker, the session can be hijacked. By encrypting the session identifier, the identifier becomes more difficult for an attacker to hijack, decrypt, and use before the session has expired.

Description

The HTTP protocol is a stateless protocol. To maintain a session, a session identifier is used. The session identifier is a piece of data used to identify a session and a user. If the session identifier is compromised by an attacker, the session can be hijacked. By encrypting the session identifier, the identifier becomes more difficult for an attacker to hijack, decrypt, and use before the session has expired.

ℹ️ Check
Follow the procedures below for each site hosted on the IIS 10.0 web server: Access the IIS 10.0 Manager. Select the website being reviewed. Under "Management" section, double-click the "Configuration Editor" icon. From the "Section:" drop-down list, select "system.webServer/asp". Expand the "session" section. Verify the "keepSessionIdSecure" is set to "True". If the "keepSessionIdSecure" is not set to "True", this is a finding.

ℹ️ Check

Follow the procedures below for each site hosted on the IIS 10.0 web server: Access the IIS 10.0 Manager. Select the website being reviewed. Under "Management" section, double-click the "Configuration Editor" icon. From the "Section:" drop-down list, select "system.webServer/asp". Expand the "session" section. Verify the "keepSessionIdSecure" is set to "True". If the "keepSessionIdSecure" is not set to "True", this is a finding.

✔️ Fix
Follow the procedures below for each site hosted on the IIS 10.0 web server: Access the IIS 10.0 Manager. Select the website being reviewed. Under "Management" section, double-click the "Configuration Editor" icon. From the "Section:" drop-down list, select "system.webServer/asp". Expand the "session" section. Select "True" for the "keepSessionIdSecure" setting. Select "Apply" from the "Actions" pane.

✔️ Fix

Follow the procedures below for each site hosted on the IIS 10.0 web server: Access the IIS 10.0 Manager. Select the website being reviewed. Under "Management" section, double-click the "Configuration Editor" icon. From the "Section:" drop-down list, select "system.webServer/asp". Expand the "session" section. Select "True" for the "keepSessionIdSecure" setting. Select "Apply" from the "Actions" pane.