krb5 -- MITKRB5-SA-2011-003, KDC vulnerable to double-free when PKINIT enabled

An advisory published by the MIT Kerberos team says:

The MIT Kerberos 5 Key Distribution Center (KDC) daemon is vulnerable to a double-free condition if the Public Key Cryptography for Initial Authentication (PKINIT) capability is enabled, resulting in daemon crash or arbitrary code execution (which is believed to be difficult).

An unauthenticated remote attacker can induce a double-free event, causing the KDC daemon to crash (denial of service), or to execute arbitrary code. Exploiting a double-free event to execute arbitrary code is believed to be difficult.

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