"MIT Kerberos is prone to a remote denial-of-service vulnerability in
An attacker may exploit this issue to cause the affected application to
crash, denying service to legitimate users.
MIT Kerberos 5 1.5 through 1.6.3 are vulnerable. "
Patches are available for MIT Kerberos, RHEL and Ubuntu. It is
recommended that users upgrade to the latest release to avoid exploitation.