Kerberos is a secure network authentication protocol built to verify identities over untrusted networks. It uses tickets, symmetric encryption, and a trusted third-party called the Key Distribution Center (KDC). When configured correctly, it prevents password interception, replay attacks, and impersonation. But gaps in deployment or misconfiguration turn this shield into an open door.
A Kerberos security review examines every step in the authentication flow. First, the ticket-granting ticket (TGT) process must be checked for correct encryption types. Weak ciphers or mismatched configurations open risk. Second, service principal names (SPNs) require careful inventory and validation. Orphaned SPNs can be weaponized for golden ticket or silver ticket attacks. Third, time synchronization across all hosts must be tight. Kerberos rejects tickets that fall outside the allowed clock skew.
Auditing KDC logs is essential. Failed logins, unusual ticket requests, or sudden changes in SPNs can all signal intrusion attempts. Password policies for accounts with Kerberos privileges need to be strong and rotated. Review delegation settings; unconstrained delegation can expose sensitive services to attackers.