Please Install the Updated Packages.

Eric W. Biederman discovered a flaw with the mediation of mount flags in the Linux kernel's user namespace subsystem. An unprivileged user could exploit this flaw to by-pass mount restrictions, and potentially gain administrative privileges. (CVE-2014-5207) Kenton Varda discovered a flaw with read-only bind mounds when used with user namespaces. An unprivileged local user could exploit this flaw to gain full write privileges to a mount that should be read only. (CVE-2014-5206)

linux on Ubuntu 14.04 LTS