The server in Microsoft Active Directory on Windows Server 2003 SP2 does not properly handle an update request for a service principal name (SPN), which allows remote attackers to cause a denial of service (authentication downgrade or outage) via a crafted request that triggers name collisions, aka "Active Directory SPN Validation Vulnerability."
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.