Kerberos Password Change. This port is used for changing/setting passwords against Active Directory.
The fact you’re seeing this service and port suggests you may be scanning a Domain Controller, for which both UDP & TCP ports 464 are used by the Kerberos Password Change. This port in particular is used for changing/setting passwords against Active Directory.
Doing an nmap -A might help you identify which version is being run and could assist in helping you work out what type of attack it’s vulnerable against.
https://security.stackexchange.com/questions/205492/what-is-this-service