Authentication bypass by improper validation of certificate EKU and SANAn authentication bypass flaw was found in the way krb5#039;s certauth interface handled the validation of client certificates. A remote attacker able to communicate with the KDC could potentially use this flaw to impersonate arbitrary principals under rare and erroneous circumstances.Invalid S4U2Self or S4U2Proxy request causes assertion failureA denial of service flaw was found in MIT Kerberos krb5kdc service. An authenticated attacker could use this flaw to cause krb5kdc to exit with an assertion failure by making an invalid S4U2Self or S4U2Proxy request.