Maximum lifetime for user ticket

Applies to

  • Windows 10

Describes the best practices, location, values, policy management, and security considerations for the Maximum lifetime for user ticket policy setting.

Reference

The Maximum lifetime for user ticket policy setting determines the maximum amount of time (in hours) that a user’s ticket-granting ticket can be used. When a user’s ticket-granting ticket expires, a new one must be requested or the existing one must be renewed.

The possible values for this Group Policy setting are:

  • A user-defined number of hours from 0 through 99,999
  • Not defined

If the value for this policy setting is too high, users might be able to access network resources outside of their logon hours, or users whose accounts have been disabled might be able to continue to access network services by using valid service tickets that were issued before their account was disabled. If the value is set to 0, ticket-granting tickets never expire.

Best practices

  • We recommend that you set the Maximum lifetime for user ticket to 10 hours.

Location

Computer Configuration\Windows Settings\Security Settings\Account Policies\Kerberos Policy

Default Values

The following table lists the actual and effective default policy values. Default values are also listed on the policy’s property page.

Server Type or GPO Default Value
Default Domain Policy 10 hours
Default Domain Controller Policy Not defined
Stand-Alone Server Default Settings Not applicable
Domain Controller Effective Default Settings 10 hours
Member Server Effective Default Settings Not applicable
Client Computer Effective Default Settings Not applicable

Policy management

This section describes features, tools, and guidance to help you manage this policy.

A restart of the computer is not required for this policy setting to be effective.

This policy setting is configured on the domain controller.

Group Policy

Client devices will get the new setting during the next scheduled and successful Group Policy refresh. But for domain controllers to assign these new settings immediately, a gpupdate.exe /force is required. On the local computer, the Security Configuration Engine will refresh this setting in about five minutes.

Settings are applied in the following order through a Group Policy Object (GPO), which will overwrite settings on the local computer at the next Group Policy update:

  1. Local policy settings
  2. Site policy settings
  3. Domain policy settings
  4. OU policy settings

When a local setting is greyed out, it indicates that a GPO currently controls that setting.

Security considerations

This section describes how an attacker might exploit a feature or its configuration, how to implement the countermeasure, and the possible negative consequences of countermeasure implementation.

Vulnerability

If you configure the value for the Maximum lifetime for user ticket setting too high, users might be able to access network resources outside of their logon hours. Also, users whose accounts were disabled might continue to have access to network services with valid user tickets that were issued before their accounts were disabled. If you configure this value too low, ticket requests to the KDC may affect the performance of your KDC and present an opportunity for a DoS attack.

Countermeasure

Configure the Maximum lifetime for user ticket setting with a value between 4 and 10 hours.

Potential impact

Reducing this setting from the default value reduces the likelihood that the ticket-granting ticket will be used to access resources that the user does not have rights to. However, it requires more frequent requests to the KDC for ticket-granting tickets on behalf of users. Most KDCs can support a value of four hours without too much additional burden.