The system could be made to expose sensitive information.

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Ubuntu Security Notice USN-3531-3
March 29, 2018

intel-microcode update
==========================================================================

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

- Ubuntu 17.10
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

The system could be made to expose sensitive information.

Software Description:
- intel-microcode: Processor microcode for Intel CPUs

Details:

Jann Horn discovered that microprocessors utilizing speculative execution
and branch prediction may allow unauthorized memory reads via sidechannel
attacks. This flaw is known as Spectre. A local attacker could use this to
expose sensitive information, including kernel memory. (CVE-2017-5715)

This update provides the corrected microcode updates required for the
corresponding Linux kernel updates.

Update instructions:

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

Ubuntu 17.10:
  intel-microcode                 3.20180312.0~ubuntu17.10.1

Ubuntu 16.04 LTS:
  intel-microcode                 3.20180312.0~ubuntu16.04.1

Ubuntu 14.04 LTS:
  intel-microcode                 3.20180312.0~ubuntu14.04.1

After a standard system update you need to reboot your computer to make
all the necessary changes.

References:
  https://usn.ubuntu.com/usn/usn-3531-3
  https://usn.ubuntu.com/usn/usn-3531-1
  CVE-2017-5715

Package Information:
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20180312.0~ubuntu17.10.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20180312.0~ubuntu16.04.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20180312.0~ubuntu14.04.1