Skip to content
OpenAdvisories
Medium USN-3756-1 3 CVEs

intel-microcode vulnerabilities

Published Aug 27, 2018 · Updated Jun 3, 2026

Summary

It was discovered that memory present in the L1 data cache of an Intel CPU
core may be exposed to a malicious process that is executing on the CPU
core. This vulnerability is also known as L1 Terminal Fault (L1TF). A local
attacker in a guest virtual machine could use this to expose sensitive
information (memory from other guests or the host OS). (CVE-2018-3646)

Jann Horn and Ken Johnson discovered that microprocessors utilizing
speculative execution of a memory read may allow unauthorized memory reads
via a sidechannel attack. This flaw is known as Spectre Variant 4. A local
attacker could use this to expose sensitive information, including kernel
memory. (CVE-2018-3639)

Zdenek Sojka, Rudolf Marek, Alex Zuepke, and Innokentiy Sennovskiy
discovered that microprocessors that perform speculative reads of
system registers may allow unauthorized disclosure of system parameters
via a sidechannel attack. This vulnerability is also known as Rogue
System Register Read (RSRE). An attacker could use this to expose
sensitive information. (CVE-2018-3640)

Fixed packages 3

ReleasePackageFixed in
Ubuntu · 14.04 LTS 14.04:LTS intel-microcode 3.20180807a.0ubuntu0.14.04.1
Ubuntu · 16.04 LTS 16.04:LTS intel-microcode 3.20180807a.0ubuntu0.16.04.1
Ubuntu · 18.04 LTS 18.04:LTS intel-microcode 3.20180807a.0ubuntu0.18.04.1

Vulnerabilities 3

References

  • report
    https://ubuntu.com/security/CVE-2018-3639
  • report
    https://ubuntu.com/security/CVE-2018-3640
  • report
    https://ubuntu.com/security/CVE-2018-3646