The Kerberos user ticket lifetime must be limited to a maximum of 10 hours or less.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-2378	AD.4031_2008_R2	SV-36180r1_rule	ECSC-1	Medium

Description
In Kerberos, there are 2 types of tickets: Ticket Granting Tickets (TGTs) and Service Tickets. Kerberos tickets have a limited lifetime so the time an attacker has to implement an attack is limited. This policy controls how long TGTs can be renewed. With Kerberos, the user’s initial authentication to the domain controller results in a TGT which is then used to request Service Tickets to resources. Upon startup, each computer gets a TGT before requesting a service ticket to the domain controller and any other computers it needs to access. For services that startup under a specified user account, users must always get a TGT first, then get Service Tickets to all computers and services accessed.

Description

In Kerberos, there are 2 types of tickets: Ticket Granting Tickets (TGTs) and Service Tickets. Kerberos tickets have a limited lifetime so the time an attacker has to implement an attack is limited. This policy controls how long TGTs can be renewed. With Kerberos, the user’s initial authentication to the domain controller results in a TGT which is then used to request Service Tickets to resources. Upon startup, each computer gets a TGT before requesting a service ticket to the domain controller and any other computers it needs to access. For services that startup under a specified user account, users must always get a TGT first, then get Service Tickets to all computers and services accessed.

STIG	Date
Windows Server 2008 R2 Domain Controller Security Technical Implementation Guide	2012-09-05

Details

Check Text ( C-39119r1_chk )
Analyze the system using the Security Configuration and Analysis snap-in. Expand the Security Configuration and Analysis tree view. Navigate to Account Policies -> Kerberos Policy. If the value for “Maximum lifetime for user ticket” is 0 or greater than 10 hours, this is a finding.

Fix Text (F-34268r1_fix)
Set the Kerberos policy option "Maximum lifetime for user ticket" to a maximum of 10 hours, but not 0 which equates to “Ticket doesn’t expire”.