This indicates an attack attempt to exploit an Authentication Bypass vulnerability on Kerberos KDC in Microsoft Windows.
The vulnerability is due to an error when the vulnerable software handles malicious Kerberos request. A remote attacker can exploit this to gain elevated privileges on vulnerable systems.
Windows Server 2003
Windows Server 2008
Windows Server 2012
Security Bypass: Remote attackers can bypass security checks of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.