Ubuntu Security Notice 881-1 – It was discovered that Kerberos did not correctly handle invalid AES blocks. An unauthenticated remote attacker could send specially crafted traffic that would crash the KDC service, leading to a denial of service, or possibly execute arbitrary code with root privileges.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/85037/USN-881-1.txt
Source: https://packetstormsecurity.com/files/85037/Ubuntu-Security-Notice-881-1.html