The system could be made to crash or run programs as an administrator.
It was discovered that the KVM subsystem in the Linux kernel did not properly keep track of nested levels in guest page tables. A local attacker in a guest VM could use this to cause a denial of service (host OS crash) or possibly execute arbitrary code in the host OS.
21 November 2017
A security issue affects these releases of Ubuntu and its derivatives:
The system could be made to crash or run programs as an administrator.
It was discovered that the KVM subsystem in the Linux kernel did not properly keep track of nested levels in guest page tables. A local attacker in a guest VM could use this to cause a denial of service (host OS crash) or possibly execute arbitrary code in the host OS.
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. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well.
Vulmon