Microsoft Windows Kerberos Improper Authorization ResetNightmare

ResetNightmare is an authorization flaw in the Microsoft Kerberos Change Password protocol. On an unpatched domain controller, an attacker who can write the userPrincipalName attribute of a controlled account can obtain a kadmin/changepw ticket whose client name identifies another account while its PAC identifies the controlled account. The module temporarily changes the controlled account's UPN to the target sAMAccountName, requests a kadmin/changepw ticket with an NT-ENTERPRISE client name, restores the original UPN, and uses the ticket in an RFC 3244 password-change exchange. The target credentials are verified and stored as an Impact identity by default. The controlled account can be an existing user or computer whose cleartext password is known and whose userPrincipalName can be modified.