Description: The remote host is missing an update to krb5 announced via advisory USN-1088-1.
Details follow:
Cameron Meadors discovered that 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. This could allow a remote attacker to cause a denial of service.
Solution: The problem can be corrected by upgrading your system to the following package versions:
Ubuntu 9.10: krb5-kdc 1.7dfsg~ beta3-1ubuntu0.12
Ubuntu 10.04 LTS: krb5-kdc 1.8.1+dfsg-2ubuntu0.8
Ubuntu 10.10: krb5-kdc 1.8.1+dfsg-5ubuntu0.6
In general, a standard system update will make all the necessary changes.