Kerberos Security Feature Bypass Vulnerability

A security feature bypass vulnerability exists in Windows when Kerberos improperly handles a password change request and falls back to NT LAN Manager (NTLM) Authentication Protocol as the default authentication protocol.

An attacker who successfully exploited this vulnerability could use it to bypass Kerberos authentication. To exploit this vulnerability, an attacker would have to be able to launch a man-in-the-middle (MiTM) attack against the traffic passing between a domain controller and the target machine.

The update addresses this vulnerability by preventing Kerberos from falling back to NTLM as the default authentication protocol during a domain account password change.