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             AUSCERT External Security Bulletin Redistribution

                  USN-4303-1: Linux kernel vulnerability
                               18 March 2020


        AusCERT Security Bulletin Summary

Product:           kernel
Publisher:         Ubuntu
Operating System:  Ubuntu
Impact/Access:     Access Confidential Data -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2020-2732  

Reference:         ESB-2020.0945

Original Bulletin: 

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

USN-4303-1: Linux kernel vulnerability
17 March 2020

linux, linux-aws, linux-kvm vulnerability
A security issue affects these releases of Ubuntu and its derivatives:

  o Ubuntu 16.04 LTS


The system could be made to expose sensitive information.

Software Description

  o linux - Linux kernel
  o linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  o linux-kvm - Linux kernel for cloud environments


Paulo Bonzini discovered that the KVM hypervisor implementation in the Linux
kernel could improperly let a nested (level 2) guest access the resources of a
parent (level 1) guest in certain situations. An attacker could use this to
expose sensitive information.

Update instructions

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

Ubuntu 16.04 LTS
    linux-image-4.4.0-1068-kvm - 4.4.0-1068.75
    linux-image-4.4.0-1104-aws - 4.4.0-1104.115
    linux-image-4.4.0-176-generic - 4.4.0-176.206
    linux-image-4.4.0-176-generic-lpae - 4.4.0-176.206
    linux-image-4.4.0-176-lowlatency - 4.4.0-176.206
    linux-image-4.4.0-176-powerpc-e500mc - 4.4.0-176.206
    linux-image-4.4.0-176-powerpc-smp - 4.4.0-176.206
    linux-image-4.4.0-176-powerpc64-emb - 4.4.0-176.206
    linux-image-4.4.0-176-powerpc64-smp - 4.4.0-176.206
    linux-image-aws -
    linux-image-generic -
    linux-image-generic-lpae -
    linux-image-kvm -
    linux-image-lowlatency -
    linux-image-powerpc-e500mc -
    linux-image-powerpc-smp -
    linux-image-powerpc64-emb -
    linux-image-powerpc64-smp -
    linux-image-virtual -

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.


  o CVE-2020-2732

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