Title

The Kerberos policy option "Maximum tolerance for computer clock synchronization" must be set to a maximum of 5 minutes or less. (Cat II impact)

Discussion

This setting determines the maximum time difference (in minutes) that Kerberos will tolerate between the time on a client's clock and the time on a server's clock while still considering the two clocks synchronous. In order to prevent replay attacks, Kerberos uses timestamps as part of its protocol definition. For timestamps to work properly, the clocks of the client and the server need to be in sync as much as possible.

Check Content

Fix Text

Configure the Kerberos policy option Maximum tolerance for computer clock synchronization to a maximum of 5 minutes or less.

Additional Identifiers

Rule ID: SV-28505r1_rule

Vulnerability ID: V-2380

Group Title: Kerberos - Computer Clock Sync

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.