A flaw was found in the OTP kdcpreauth module of MIT Kerberos. A remote attacker could use this flaw to bypass the requires_preauth flag on a client principal and obtain a ciphertext encrypted in the principal"s long-term key. This ciphertext could be used to conduct an off-line dictionary attack against the user"s password.It was found that the krb5_read_message function of MIT Kerberos did not correctly sanitize input, and could create invalid krb5_data objects. A remote, unauthenticated attacker could use this flaw to crash a Kerberos child process via a specially crafted request.