krb5 -- double-free vulnerabilities

An advisory published by the MIT Kerberos team says:

The MIT Kerberos 5 implementation’s Key Distribution Center
(KDC) program contains a double-free vulnerability that
potentially allows a remote attacker to execute arbitrary code.
Compromise of a KDC host compromises the security of the entire
authentication realm served by the KDC. Additionally, double-free
vulnerabilities exist in MIT Kerberos 5 library code, making
client programs and application servers vulnerable.

Double-free vulnerabilities of this type are not believed to be
exploitable for code execution on FreeBSD systems. However,
the potential for other ill effects may exist.