The Key Distribution Center (KDC) in Kerberos 5 (krb5) 1.2.7 and earlier allows remote, authenticated attackers to cause a denial of service (crash) on KDCs within the same realm using a certain protocol request that causes the KDC to corrupt its heap (aka "buffer underrun").
The kadm_ser_in function in (1) the Kerberos v4compatibility administration daemon (kadmind4) in the MIT Kerberos 5 (krb5) krb5-1.2.6 and earlier, (2) kadmind in KTH Kerberos 4 (eBones) before 1.2.1, and (3) kadmind in KTH Kerberos 5 (Heimdal) before 0.5.1 when compiled with Kerberos 4 support, does not properly verify the length field of a request, which allows remote attackers to execute arbitrary code via a buffer overflow attack.
Buffer overflow in MIT Kerberos 5 (krb5) 1.2.2 and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary code via base-64 encoded data, which is not properly handled when the radix_encode function processes file glob output from the ftpglob function.