Details of a number of libxml2 vulnerabilities that have been found and fixed in Ubuntu 15.10, Ubuntu 15.04, Ubuntu 14.04 LTS, and Ubuntu 12.04 LTS have been published Ubuntu security notice blog. According to the summary – “Several security issues were fixed in libxml2.“ libxml2 incorrectly handled certain XML data. If a user or automated system were tricked into opening a specially crafted document, an attacker could possibly cause resource consumption, resulting in a denial of service.
This article is a step by step tutorial on how to upgrade your Ubuntu 12.04 LTS Precise Pangolin to Ubuntu 14.04 Trusty Tahr. This upgrade is been carried out on a VirtualBox, I cannot guaranty if this would work in your case or not. Care needs to be taken if upgrading a LIVE system. Step 1: Backup your Data – I am afraid you would have to backup your files and documents.