=========================================================================== Ubuntu Security Notice USN-3353-3 July 24, 2017 heimdal vulnerability =========================================================================== A security issue affects these releases of Ubuntu and its derivatives: Ubuntu 12.04 LTS Summary Heimdal could allow unintended access to network services. Software description heimdal - Heimdal Kerberos Network Authentication Protocol Details USN-3353-1 fixed a vulnerability in Heimdal. This update provides the corresponding updade for Ubuntu 12.04 ESM. Original advisory details: Jeffrey Altman, Viktor Dukhovni, and Nicolas Williams discovered that Heimdal clients incorrectly trusted unauthenticated portions of Kerberos tickets. A remote attacker could use this to impersonate trusted network services or perform other attacks. Update instructions The problem can be corrected by updating your system to the following package version: Ubuntu 12.04 LTS: libkrb5-26-heimdal 1.6~git20120311.dfsg.1-2ubuntu0.2 To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades. After a standard system update you need to restart any applications using Heimdal libraries to make all the necessary changes. References https://www.ubuntu.com/usn/usn-3353-3 https://www.ubuntu.com/usn/usn-3353-1 CVE-2017-11103