Overly broad permissions can turn one compromised account into a much larger security problem. Learn how to reduce unnecessary access, review privileges, and apply least privilege across modern Linux systems. Review Linux Privileges×

Alerts This Week
Warning Icon 1 544
Alerts This Week
Warning Icon 1 544

Ubuntu 16.04 LTS USN-3484-2 Critical: KVM Denial Of Service

ubuntu
Calendar Grey November 21, 2017
Scroller Ubuntu
The latest Ubuntu Security Alert USN-3484-2 highlights a critical flaw in KVM that impacts the HWE kernel, potentially leading to system instability.
The system could be made to crash or run programs as an administrator.

Summary

The system could be made to crash or run programs as an administrator.

Software Description:

- linux-hwe: Linux hardware enablement (HWE) kernel

Details:

USN-3484-1 fixed vulnerabilities in the Linux kernel for Ubuntu 17.04.

This update provides the corresponding updates for the Linux Hardware

Enablement (HWE) kernel from Ubuntu 17.04 for Ubuntu 16.04 LTS.

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.

Topics%20covered

Topics Covered

security advisory denial of service critical ubuntu kvm

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 16.04 LTS:
  linux-image-4.10.0-40-generic   4.10.0-40.44~16.04.1
  linux-image-4.10.0-40-generic-lpae  4.10.0-40.44~16.04.1
  linux-image-4.10.0-40-lowlatency  4.10.0-40.44~16.04.1
  linux-image-generic-hwe-16.04   4.10.0.40.42
  linux-image-generic-lpae-hwe-16.04  4.10.0.40.42
  linux-image-lowlatency-hwe-16.04  4.10.0.40.42

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.

References

https://ubuntu.com/security/notices/USN-3484-2

https://ubuntu.com/security/notices/USN-3484-1

CVE-2017-12188

Severity
critical
Lowest
Low
Medium
High
Critical

November 21, 2017

Topics%20covered

Topics Covered

security advisory denial of service critical ubuntu kvm

Package Information

https://launchpad.net/ubuntu/+source/linux-hwe/4.10.0-40.44~16.04.1

Get the latest News and Insights

Get the latest Linux and open source security news straight to your inbox.