krb5 -- MITKRB5-SA-2011-004, kadmind invalid pointer free() [CVE-2011-0285]

An advisory published by the MIT Kerberos team says:

The password-changing capability of the MIT krb5 administration
daemon (kadmind) has a bug that can cause it to attempt to free()
an invalid pointer under certain error conditions. This can cause
the daemon to crash or induce the execution of arbitrary code
(which is believed to be difficult). No exploit that executes
arbitrary code is known to exist, but it is easy to trigger a
denial of service manually.
Some platforms detect attempted freeing of invalid pointers and
protectively terminate the process, preventing arbitrary code
execution on those platforms.