What Eventcode 4771?
What Eventcode 4771?
4771: Kerberos pre-authentication failed. This event is logged on domain controllers only and only failure instances of this event are logged. At the beginning of the day when a user sits down at his or her workstation and enters his domain username and password, the workstation contacts a local DC and requests a TGT.
What is error code 0X12?
Failure code 0x12 very specifically means “Clients credentials have been revoked”, which means that this error has happened once the account has been disabled, expired, or locked out.
What is pre-authentication failed?
This problem can occur when a domain controller doesn’t have a certificate installed for smart card authentication (for example, with a “Domain Controller” or “Domain Controller Authentication” template), the user’s password has expired, or the wrong password was provided.
Do you not need Kerberos Preauthentication?
Without Kerberos Pre-Authentication a malicious attacker can directly send a dummy request for authentication. The KDC will return an encrypted TGT and the attacker can brute force it offline.
Does Windows 10 use Kerberos?
Windows 10 Kerberos is a client-server authentication protocol used on multiple operating systems, including Windows.
Should I disable Kerberos?
Microsoft says that “Disabling Kerberos Pre-Authentication must not be disabled“. Without Kerberos Pre-Authentication a malicious attacker can directly send a dummy request for authentication. The KDC will return an encrypted TGT and the attacker can brute force it offline.
What is Kerberos Preauthentication?
Kerberos Pre-Authentication is a security feature which offers protection against password-guessing attacks. The AS request identifies the client to the KDC in Plaintext. If Kerberos Pre-Authentication is enabled, a Timestamp will be encrypted using the user’s password hash as an encryption key.
What does Windows Security log event ID 4771?
If the ticket request fails Windows will either log this event, failure 4771, or 4768 if the problem arose during “pre-authentication”. In Windows Kerberos, password verification takes place during pre-authentication.
What is event ID 4771 for Kerberos failed?
4771: Kerberos pre-authentication failed. This event is logged on domain controllers only and only failure instances of this event are logged. At the beginning of the day when a user sits down at his or her workstation and enters his domain username and password, the workstation contacts a local DC and requests a TGT.
What does event ID 4768 mean on Windows?
Windows logs other instances of event ID 4768 when a computer in the domain needs to authenticate to the DC typically when a workstation boots up or a server restarts. In these instances, you’ll find a computer name in the User Name and fields. Computer generated kerberos events are always identifiable by the $ after the computer account’s name.
