Operating System:

[Ubuntu]

Published:

22 November 2017

Protect yourself against future threats.

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===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2017.2978
                        Linux kernel vulnerability
                             22 November 2017

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           linux
                   linux-raspi2
                   linux-hwe
                   linux-gcp
Publisher:         Ubuntu
Operating System:  Ubuntu
Impact/Access:     Execute Arbitrary Code/Commands -- Existing Account
                   Denial of Service               -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-12188  

Original Bulletin: 
   http://www.ubuntu.com/usn/usn-3484-1
   http://www.ubuntu.com/usn/usn-3484-2
   http://www.ubuntu.com/usn/usn-3484-3

Comment: This advisory references vulnerabilities in the Linux kernel that 
         also affect distributions other than Ubuntu. It is recommended that
         administrators running Linux check for an updated version of the 
         kernel for their system.
         
         This bulletin contains three (3) Ubuntu security advisories.
         All advisories pertain to the same bugfix for different kernels.

- --------------------------BEGIN INCLUDED TEXT--------------------

==========================================================================
Ubuntu Security Notice USN-3484-1
November 21, 2017

linux, linux-raspi2 vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- - Ubuntu 17.04

Summary:

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

Software Description:
- - linux: Linux kernel
- - linux-raspi2: Linux kernel for Raspberry Pi 2

Details:

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.

Update instructions:

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

Ubuntu 17.04:
  linux-image-4.10.0-1021-raspi2  4.10.0-1021.24
  linux-image-4.10.0-40-generic   4.10.0-40.44
  linux-image-4.10.0-40-generic-lpae  4.10.0-40.44
  linux-image-4.10.0-40-lowlatency  4.10.0-40.44
  linux-image-generic             4.10.0.40.40
  linux-image-generic-lpae        4.10.0.40.40
  linux-image-lowlatency          4.10.0.40.40
  linux-image-raspi2              4.10.0.1021.22

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://www.ubuntu.com/usn/usn-3484-1
  CVE-2017-12188

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.10.0-40.44
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.10.0-1021.24



==========================================================================
Ubuntu Security Notice USN-3484-2
November 21, 2017

linux-hwe vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- - Ubuntu 16.04 LTS

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.

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://www.ubuntu.com/usn/usn-3484-2
  https://www.ubuntu.com/usn/usn-3484-1
  CVE-2017-12188

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


==========================================================================
Ubuntu Security Notice USN-3484-3
November 21, 2017

linux-gcp vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- - Ubuntu 16.04 LTS

Summary:

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

Software Description:
- - linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems

Details:

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.

Update instructions:

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

Ubuntu 16.04 LTS:
  linux-image-4.10.0-1009-gcp     4.10.0-1009.9
  linux-image-gcp                 4.10.0.1009.11

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://www.ubuntu.com/usn/usn-3484-3
  https://www.ubuntu.com/usn/usn-3484-1
  CVE-2017-12188

Package Information:
  https://launchpad.net/ubuntu/+source/linux-gcp/4.10.0-1009.9

- --------------------------END INCLUDED TEXT--------------------

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===========================================================================
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