Several security issues were fixed in the kernel.
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)
18 August 2014
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the kernel.
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)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to reboot your computer to make all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. If you use linux-restricted-modules, you have to update that package as well to get modules which work with the new kernel version. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-server, linux-powerpc), a standard system upgrade will automatically perform this as well.
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